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Appendix:Dictionary of Mining, Mineral, and Related Terms/M/6

muck bar
 * Gray, forge pig iron melted in a puddling furnace, then balled, squeezed, and rolled.

muck boss
 * In bituminous coal mining, a person who is in charge of a crew of loaders shoveling rock into cars during the driving of new underground passageways from one part of the mine to another.

mucker
 * In mining and quarrying, a laborer who (1) shovels ore or rock into mine cars or onto a conveyor from which mine cars are loaded and at some point are removed from the working face or surfaces of natural stone deposits; or (2) works in a stope shoveling ore into chutes from which it is loaded into cars on haulage level below. Also called car filler; rock passer; shoveler.

mucking
 * The operation of loading broken rock by hand or machine, usually in shafts or tunnels.

muck iron
 * Crude puddled iron ready for squeezing or rolling.

muckle
 * Soft clay overlying or underlying coal.

muckle hammer
 * A scaling or spalling hammer.

muck saw
 * A saw using an uncharged blade, usually steel, which runs in a bath or stream of carborundum abrasive. Also known as a mud saw.

muck shifting
 * Operations concerned with stripping overburden, valuable gravels, or sands in exploitation of opencast mineral deposits.

muck soil
 * A soil that contains at least 50% organic matter that is well decomposed.

mucky hole
 * In a furnace, a taphole from which the iron is so pasty that it does not run freely.

mud
 * a. A sticky or slippery mixture of water and silt- or clay-sized earth material, with a consistency ranging from semifluid to soft and plastic; a wet, soft soil or earthy mass; mire, sludge.

b. An unconsolidated sediment consisting of clay and/or silt, together with material of other dimensions (such as sand), mixed with water. c. A suspension made by mixing the drill circulation fluid (water) with the fine cuttings produced by the bit when drilling a borehole.

mud auger
 * A diamond-point bit with the wings of the point twisted in a shallow, augerlike spiral. Also called clay bit; diamond-point bit. See also: mud bit.

mud balance
 * An instrument used to measure the density of drill mud.

mud barrel
 * a. A double-tube core barrel with a greater-than-normal clearance between the inner and outer tubes, for use with mud-laden circulation liquids.

b. A bailing device to bring to the surface the cuttings formed by the action of the bit at the bottom of a borehole in free-fall or churn drilling. c. A small bailer.

mud belt
 * The belt of marine deposits composed largely of detrital clay, and lying between the coarser terrigenous sediments to the landward and the deep oceanic organic oozes on the seaward side. At present, the inner boundary of the inner mud belt is the edge of the continental shelf.

mud bit
 * A pointed-edge, chisellike tool used for boring drill holes through clay or claylike overburden materials. Also called clay bit; diamond-point bit. See also: mud auger.

mud blasting
 * In this method, sticks of explosive are stuck on the side of a boulder with a covering of mud, and when detonated, very little of the energy of the explosive is used in breaking the boulder.

mud bucket
 * The bucket attached to a dredger.

mud cake
 * The material filling the cracks, crevices, pores, etc., of the rock or adhering to the walls of a borehole. The cake may be derived from the drill cuttings, circulating drill mud, or both; it is formed when the water in the drilling mud filters into porous formations, leaving the mud ingredients as a caked layer adhering to the walls of the borehole. Syn: cake; mud wall cake.

mudcap
 * A charge of dynamite, or other high explosive, fired in contact with the surface of a rock after being covered with quantity of wet mud, wet earth, or sand, no borehole being used. The slight confinement given the dynamite by the mud or other material permits part of the energy of the dynamite being transmitted to the rock in the form of a blow. A mudcap may be placed on top or to one side, or even under a rock, if supported, with equal effect. Also called adobe; dobie; sandblast.

mudcap method
 * See: secondary blasting.

mudcapping
 * Method for blasting rock without drilling, in which an explosive is placed on top of the rock and covered by a cap of mud or earth. Syn: adobe charge.

mud cast
 * See: mud crack.

mud column
 * The length in feet (meters), as measured from the bottom of a borehole of a drill-mud liquid standing in a borehole either while being circulated during drilling operations or when the drill string is not in the hole. Syn: column of mud.

mud crack
 * a. The filling of desiccation cracks in mud, customarily in sandstone; generally preserved as raised ridges (casts) arranged in polygonal patterns on the underside of a sandstone bed.

b. An irregular fracture in a crudely polygonal pattern, formed by the shrinkage of clay, silt, or mud, generally in the course of drying. Syn: sun crack; mud cast; shrinkage crack; desiccation crack.

mudding
 * Filling voids with clay in limestone from which sulfur has been extracted.

mudding off
 * In petroleum production, commonly thought of as reduced productivity caused by the penetrating, sealing, or plastering effect of a drilling fluid. Actually there is little penetration into the capillaries of an ordinary producing formation, and a slight amount of differential back pressure will remove even thick filter cakes.

mudflow
 * A general term for a mass-movement landform and a process characterized by a flowing mass of predominantly fine-grained earth material possessing a high degree of fluidity during movement. The water content of mudflows may range up to 60%. With increasing fluidity, mudflows grade into loaded and clear streams; with a decrease in fluidity, they grade into earthflows. Syn: lahar.

mud gun
 * An apparatus for pushing a clay stopper into the taphole of a blast furnace. A steam cylinder operates a plunger inside a steel tube into which clay is fed from a hopper tube as the plunger is worked back and forth, and is thus forced into the taphole at the end of a cast. See also: clay gun.

mud hog
 * a. A pump used to circulate mud-laden drill fluid during borehole drilling operations. See also: mud pump; sludge pump.

b. Pressure tunnel worker. c. A machine for the disintegration of dry or moist plastic clay. It consists of a rotating swing hammer operating close to a series of anvils linked together to form a steeply inclined slat conveyor.

mud-laden
 * Said of a liquid (usually water) mixed with finely ground earthy or clayey materials.

mud-laden fluid
 * The water or oil in which mudlike solids are suspended; used to support the open bore and cool and clear the cuttings from a drill bit. The fluid is circulated while rotary- and/or diamond-drilling a borehole. See also: drilling mud.

mudline
 * Line of demarcation between fairly clear supernatant water and settling solids in a thickener or other sedimentation vessel.

mud log
 * A continuous analysis of the drilling mud and well cuttings during rotary drilling for entrained oil or gas. Visual observation, ultraviolet fluoroscopy, partition gas chromatograph, and hydrogen-flame ionization analyzer may be used. A drilling-time log is kept concurrently.

mud logging
 * a. A method of determining the presence or absence of oil, gas, and salt water in the various formations penetrated by a drill bit. The drilling fluid and the cuttings are continuously tested on their return to the surface, and the results of these tests are correlated with the depth of origin.

b. A mud log is a recording vs. depth of the parameters being monitored. Basic parameters monitored are: bit weight, rotary speed, rotary torgue, mud weight, gas content (trip and background) cutting analysis, pit volume, flow rate, pump pressure (strokes), hole depth, and chlorides. This is a common service used to obtain data from the mud system and drilling parameters.

mud mixer
 * A machine, pump, hopper, or other apparatus used to mix dry ingredients with water or other liquids to prepare a drill mud. Also called atomizer; jet mixer; mixer. Syn: emulsifier.

mud pot
 * a. A type of hot spring containing boiling mud, usually sulfurous and often multicolored, as in a paint pot. Mud pots are commonly associated with geysers and other hot springs in volcanic areas, esp. Yellowstone National Park, WY.

b. A geyser that throws up mud. Also called mud geyser.

mud pump
 * a. The circulating pump that supplies fluid to a rotary drill. Also called slush pump. See also: mud hog.

b. See: circulating pump.

mud ring
 * a. The section of a boiler where scale, alkalies, and sediment collect.

b. The ring or frame forming the bottom of a water leg in a steam boiler.

mud rush
 * The more or less sudden inflow of peat, moss, sand, gravel, silt, or any other waterlogged material into shallow mine workings. The manager has a duty to take steps to prevent such inrushes as laid down in the Precautions against Inrushes Regulations, 1956. Also called mud run. See also: inrush of water; running ground.

mud scow
 * A flatboat or barge for the transportation of mud, generally used in connection with dredges.

mud snapper
 * An 11-in-long (28-cm-long), 3-lb (1.4-kg) clamshell-type snapper attached to the bottom of a sounding lead by means of a hole drilled in the lead. The jaws are cast bronze and are actuated by a spring. The jaws are held open by engaging two trigger pins within the jaws. The mud snapper and sounding lead may be operated in shallow water by hand lowering or by lowering from a bathythermograph or oceanographic winch.

mud socket
 * A device attached to drill rods and used to remove sand from a borehole. CF: mule shoe.

mudstone
 * a. An indurated mud having the texture and composition of shale, but lacking its fissility; a blocky or massive, fine-grained sedimentary rock in which the proportions of clay and silt are approx. equal; a nonfissile mud shale. See also: claystone; siltstone.

b. A general term that includes clay, silt, claystone, siltstone, shale, and argillite.

mudstone ratio
 * A uranium prospector's term, esp. on the Colorado Plateau, for the ratio of the total thickness of red mudstone to that of green mudstone within an assumed stratigraphic interval. Its value is based upon the premise that uranium-bearing solutions will bleach red mudstone containing ferric iron to green mudstone containing ferrous iron in the course of depositing uranium minerals.

mudstone trap
 * A place where uranium mineralization has been trapped at a mudstone-sandstone interface.

mud sump
 * In drilling operations, a mud pit.

mud up
 * a. The act or process of filling, choking, or clogging the waterways of a bit with consolidated drill cuttings. Also called sludging; sludging up.

b. The act or process of filling the pores or cracks in the rock surrounding a borehole; also, to cause mud to adhere to the walls of a borehole.

mud viscosity
 * The property of a mud-laden fluid to resist flow due to internal friction and the combined effects of adhesion and cohesion; e.g., a Marsh funnel (used to measure the viscosity of mud) will discharge 1 quart (0.95 L) of water in about 36 s, whereas an equal volume of an average drilling mud is discharged in 40 to 55 s or more from the same funneI.

mud volcano
 * An accumulation, usually conical, of mud and rock ejected by volcanic gases; also, a similar accumulation formed by escaping petroliferous gases.

mud wall cake
 * a. See: mud cake.

b. The formation of mud in the drilling fluid by adhering to the wall of the hole. When the drilling mud particles comes in contact with porous, permeable formation, solid particles immediately enter the openings. This sealing property is dependent upon the amount and physical state of the colloidal material in the mud.

muffle
 * a. A semi-cylindrical or long, arched oven (usually small and made of fireclay), heated from outside, in which substances may be exposed at high temperature to an oxidizing atmospheric current, and kept at the same time from contact with the gases from the fuel. Cupellation and scorification assays are performed in muffles; on a larger scale, copper ores were formerly roasted in muffle furnaces.

b. An enclosure in a furnace to protect the ware from the flame and products of combustion.

muffle furnace
 * a. A furnace with an externally heated chamber, the walls of which radiantly heat the contents of the chamber.

b. A furnace in which heat is applied to the outside of a refractory chamber containing the charge. The charge may be held in a muffle, crucible retort, or other enclosure that is enveloped by the hot flame gases, and the heat must reach the charge by flowing through the walls of the container.

muffle kiln
 * a. An arched fireclay-lined furnace in which seggars are placed.

b. A kiln in which combustion of the fuel takes place within refractory muffles, which, in turn, conduct heat into the ware chamber.

muffler
 * A muffler that concentrates on suppressing sound waves vibrating 200 to 2,000 times a second--the loudest and most objectionable ones created by rock drills. Because the muffler bypasses the lower frequencies, it does not interfere with the column of air that makes a pneumatic drill function.

mugearite
 * Orthoclase-bearing oligoclase basalt, with major olivine, accessory apatite, and opaque oxides. Pyroxene may or may not be present. See also: trachyandesite.

mule
 * a. A small car, or truck, used to push cars up a slope or inclined plane.

b. See: pusher. c. An extra worker who helps push the loaded cars out in case of an upgrade, etc.; from Joplin, Mo.

mule's foot
 * Kansas. An extension bit used in boring coal.

mule shoe
 * A short length of tubing coupled to the bottom of a drill string to wash and clean out sand or mud from a borehole, the washing action being aided by cutting off the bottom end of the tubing at an angle of 45 degrees to its longitudinal axis. Also called mud socket.

mule skinner
 * A mule driver.

muleway
 * Heavily timbered passage between levels in a mine for the transfer of unattached mules from one level to the other.

muller
 * a. Stone, iron shoe, or heavy steel rubbing disk, used to bear down upon rock in comminution.

b. A heavy grinding wheel that is the crushing and mixing member in a dry or wet pan. c. See: bucking iron.

mulling
 * Mixing sand and clay particles by a rolling, grinding, rubbing, or stirring action.

mullion structure
 * A wavelike pattern of parallel grooves and ridges, measuring as much as several feet from crest to crest, and formed on a folded surface or along a fault surface. CF: slickensides.

mullite
 * An orthorhombic mineral consisting of an aluminum silicate that is resistant to corrosion and heat; used as a refractory. Also known as porcelainite.

mullock
 * See: muck.

multibucket excavator
 * A machine similar to a dredger used for excavating cuttings for roads, railways, or canals. One large machine of this type can dig 100 yd/h (91.4 m/h) on a slope 25 ft (7.62 m) high.

Multicut chain
 * Trade name for a coal-cutter chain designed for use with curved jibs. It is short pitch and of high flexibility. See also: curved jib.

multideck cage
 * A cage containing two or more compartments or platforms to hold the mine cars supplies or workers. Every effort is made to keep the number of decks as low as possible for a given output in order to cut down the decking time and equipment at shaft top and bottom. See also: deck.

multideck screen
 * A screen with two or more superimposed screening surfaces mounted rigidly within a common frame.

multideck sinking platform
 * A sinking platform consisting of several decks to enable various shaft-sinking operations to be performed simultaneously. The bottom deck, in a three-deck platform, is usually suspended from four winch ropes which also act as guides for the kibbles, and the middle and top decks are supported above the bottom deck by rigid supports. The top deck is used for the manipulation of the concrete buckets and for fixing the shuttering. The center deck is used by the workers when placing the concrete, while the bottom deck carries telephone, blasting, lighting, and signaling cable drums. The lower side of the bottom deck may carry the equipment for manipulating the cactus grab.

multideck table
 * Shaking table with two or more superposed decks, independently fed and discharged but worked by one vibrating mechanism.

multifuse igniter
 * A device employed to reduce the number of fuses to be lit by the miner before retiring to safety. By means of a multifuse igniter, it is possible to remotely fire stopes or headings primed with plain detonators and safety fuse.

multihearth furnace
 * Roasting furnace with several hearths vertically superposed. Material is raked downward by horizontally rotating rabbles, so as to work alternately to the periphery and center of successive hearths, encountering roasting heat as it gravitates downward.

multijib cutter
 * A cutter loader with a number of horizontal jibs similar to a coal cutter. Loose coal is diverted onto the conveyor by gummer and plow plate. The machine is usually used in seams up to about 3 ft (0.9 m) in thickness with a clean roof parting. The depth of cut varies up to 4 ft (1.2 m). Coal degradation is considerable.

multilayer bit
 * A bit set with diamonds arranged in successive layers beneath the surface of the crown. CF: impregnated bit; surface-set bit.

multilock lode
 * Lode that occupies a shear zone. Such a zone has no definite walls, the ore gradually shading off into country rock. It is probable that the gold of some rich alluvial fields came from shear zones.

multilouvre dryer
 * A dryer whose moving element consists of two strands of roller chain with specially designed flights, suspended in such a way as to provide means for keeping the bed in a constantly flowing mass. The material flows in a shallow bed over the ascending flights and at the same time is gradually moved across the dryer from the feed point to the discharge point. The gases are pulled from the furnace and through the flowing bed of coal. The entire area of the dryer is covered by suction from the exhaust fan. See also: thermal drying.

multiphase
 * See: polyphase.

multiple-arch dam
 * A lightweight dam constructed of repeated arches with axes sloping at about 45 degrees to the horizontal, the arches being carried on parallel buttress walls.

multiple-bench quarrying
 * The method of quarrying a rock ledge in a series of successive benches or steps.

multiple detectors
 * Two or more seismic detectors whose combined output energy is fed into a single amplifier-recorder circuit. This technique is used to cancel undesirable near-surface waves. Syn: multiple geophones; multiple recording groups.

multiple dike
 * A dike made up of two or more intrusions of the same kind of igneous rock.

multiple-entry system
 * A system of access or development openings, generally in bituminous coal mines, involving more than one pair of parallel entries, one for haulage and fresh air intake and the other for return air. Multiple-entry systems permit circulation of large volumes of air.

multiple-expansion engine
 * An engine driven by steam or compressed air expanding in two or more stages.

multiple fault
 * A structure consisting of several parallel faults in close proximity with no distortion. See also: step fault.

multiple firing
 * Firing electrically with delay blasting caps in a number of holes at one time.

multiple fuse-igniter cartridge
 * Consists of a cardboard cartridge about 2 in long with a 3/4-in (1.9-cm) outside diameter. The closed end is coated with black powder, and the ends of eight fuses are inserted in the cartridge, in contact with the powder. A master fuse is then inserted, which, when lit, burns to the powder and ignites it. The powder flares brightly and lights the eight fuses.

multiple geophones
 * See: multiple detectors.

multiple intersections
 * a. The intercepts that cross a vein, orebody, or other geologic feature, accomplished by drilling several auxiliary boreholes from a single, main, or parent borehole with the aid of wedges and similar deflecting devices.

b. Intercepting a steeply dipping vein at various depths by changing the angle of the drill head.

multiple intrusion
 * Any type of igneous intrusion that has been produced by several injections separated by periods of crystallization. Chemical composition of the various injections is approx. the same. CF: composite intrusion.

multiple lines
 * A single line reeved around two or more sheaves so as to increase pull at the expense of speed.

multiple openings
 * Any series of underground openings separated by rib pillars or connected at frequent intervals to form a system of rooms and pillars.

multiple-ply plate
 * Steel plate made up of thicknesses of other plates of steel or steel and wrought iron welded together.

multiple recording groups
 * See: multiple detectors.

multiple ribbon belt conveyor
 * A belt conveyor having a conveying surface of two or more spaced strands of narrow flat belts.

multiple-row blasting
 * The drilling, charging, and firing of several rows of vertical holes along a quarry or opencast face. The holes may be spaced in the square pattern with delay detonators in the rows as well as row by row. The spacing of the holes will vary according to their depth, diameter, and the type of rock. See also: small-diameter blastholes.

multiple-seam mining
 * Mining two or more seams of coal, frequently close together, that can be mined profitably where mining one alone would not be profitable.

multiple seismometers
 * See: bunched seismometers.

multiple series
 * A method of wiring a large group of blasting charges by connecting small groups in series and connecting these series in parallel. Syn: parallel series.

multiple shooting
 * The firing of an entire face at one time. The holes are connected in a single series and all the holes shoot at the same instant.

multiple shot
 * See: battery of holes.

multiple-shot blasting unit
 * A multiple-shot blasting unit is designed for firing simultaneous explosive charges in mines, quarries, and tunnels. Syn: blasting unit.

multiple shotholes
 * Two or more shotholes that are shot almost simultaneously. They are so spaced as to minimize near-surface interferences that mask desired signals if only one shothole is used.

multiple-shot instrument
 * A borehole-survey instrument capable of taking and recording a series of inclination and bearing readings on a single trip into a borehole. CF: single-shot instrument.

multiple-shot survey
 * A borehole survey using a multiple-shot instrument.

multiple sill
 * A sill made up of two or more intrusions composed of the same kind of igneous rock.

multiple-speed floating control system
 * As used in flotation, a form of floating control system in which the manipulated variable may change at two or more rates each corresponding to a definite range of values of the actuating signal.

multiple splitting
 * The parting or separation of a thick seam into more than two layers of coal. See also: simple split seam.

multiple-strand chain
 * A roller chain made up of two or more strands assembled as a single structure on pins extending through the entire assembly.

multiple-strand conveyor
 * a. Any conveyor which employs two or more spaced strands of chain, belts, or cords as the load-supporting medium.

b. Any conveyor in which two or more strands are used as the propelling medium connecting pans, pallets, etc.

multiple-strand rope
 * A wire rope designed to obviate spinning due to untwisting. It is formed by a series of layers of strands built around a center fiber core. Each layer of strands is given a lay opposite to that on which it is built, each layer thus tending to impart its own twist that is cancelled by the next layer. Therefore, this rope can be used for sinking or where a free load is to be lifted. The stretch with a multiple strand rope is not so great as with round strand and flattened strand ropes. See also: multistrand rope; wire rope.

multiple twin
 * See: repeated twinning.

multiple-vent basalt
 * See: shield basalt.

multiple wedge
 * See: plug-and-feather method.

multiplow
 * A layout consisting of six or more plows, 220 lb (100 kg) each, 20 yd (18.3 m) apart on one rope or chain, feeding onto an armored conveyor; the load on the conveyor is well distributed. A driving unit is arranged at both ends of the face and operated alternately to impart a to-and-fro movement to the plows. The minimum workable seam thickness is 20 in (50.8 cm) at gradients from 0 degrees to 20 degrees ; maximum length of face is about 190 yd (174 m). See also: Gusto multiplow.

multiplying constant
 * The constant, used in stadia work, by which the staff intercept is multiplied to determine the distance between the staff and the theodolite. The value is generally taken as 100. See also: tachymeter.

multirope friction winder
 * A winding system based on the principles of the Koepe winder. The drive to the winding ropes is the frictional resistance between the ropes and the driving sheaves. Multirope friction winders are usually tower mounted, with either cages or skips, and provided with a counterweight. The sheaves are from about 6 to 12 ft (1.8 to 3.7 m) in diameter with a direct coupled or geared drive. Four ropes are favored and these operate in parallel and share the total suspended load. The system was introduced partly because of the difficulty of winding heavy loads from deep shafts with a single large-diameter winding rope. Modern winding ropes have become large and heavy, being 2-1/4 in (5.72 cm) in diameter locked coil, weighing 16.5 st (15 t) for a 1,000-yd (915-m) shaft; therefore, the introduction of the friction winder, with its counterweight, and using four smaller ropes side by side in place of one. Such ropes need be only 1-1/4 in (3.2 cm) in diameter to give equivalent breaking strain. See also: Koepe winder.

multishot firing
 * The firing of a number of shots simultaneously. See also: M.E. 6 exploder.

multishot gyroscopic instrument
 * A borehole surveying instrument that can take a number of readings during its descent and ascent in the borehole. It comprises gyroscopic and photographic recording units; direction and inclination indicators; a timing clock, and other accessories. A movie film enables numerous records to be taken throughout the depth of the borehole. See also: gelatin borehole tube.

multispectral scanner
 * A remote sensing device that is capable of recording data in the ultraviolet, visible, and infrared portions of the spectrum. Syn: shuttle multispectral infrared radiometer. See also: thematic mapper.

multistage fan
 * A fan having two or more impellers working in series.

multistrand rope
 * A flexible, nonspinning rope; composed of concentric layers of strands of relatively fine wires, alternate layers of strands being wound in opposite directions over a hemp core. See also: multiple-strand rope.

multiwheel roller
 * A heavy roller with pneumatic tires used to consolidate embankments.

mummification
 * The process of preservation of plant tissues under the influence of arrested decay.

mun
 * Corn. Any fusible metal.

mundic
 * A drillers' term for pyrite. See also: pyrite.

Munroe effect
 * The concentration of explosive effect (i.e. jetting) which occurs at a cavity at the end of an explosive charge; this effect is the basis of the design and performance of shaped charges.

muon
 * Contraction of mu-meson. An elementary particle with 207 times the mass of an electron. It may have a single positive or negative charge.

Murakami's reagent
 * An etching reagent developed for use in the investigation of the structure of iron-carbon-chromium alloys. It consists of a solution of 10 g potassium ferricyanide, 10 g potassium hydroxide, and 100 mL water.

murasakite
 * A schistose rock composed of piedmontite and quartz. See also: ollenite.

murdochite
 * An isometric mineral, PbCu (sub 6) O (sub 8) (Cl,Br) (sub 2) ; rare; secondary; forms minute black octahedra.

Murex process
 * A flotation process that is not strictly of the same class as others, but still makes use of the principle of selective oiling of sulfide particles. The crushed ore is fed into an agitator and mixed with 4% to 5% of its weight of a paste made of one part of oil or thin tar with three or four parts of magnetic oxide of iron. This oxide must be ground to an impalpable powder. These ingredients, with enough water to make a pulp, are agitated for 5 to 20 min. The paste preferentially adheres to the sulfides because of the oil. The ore is then fed over magnets, and oxide of iron, with the mineral adhering to it, is pulled out. The oil and magnetite are then recovered.

Muschamp coal miner
 * A cutter loader which is essentiaily a conversion unit for Anderton shearer machines and designed to produce a reasonable percentage of large coal. The top and bottom of the seam are cut by rotating drums of small diameter while shearing the back of the cut with a narrow-kerf jib and chain.

muscovado
 * A term applied in Minnesota to rusty-colored outcropping rocks, such as gabbros and quartzites, that resemble brown sugar. Etymol: Spanish, brown sugar.

muscovite
 * A monoclinic mineral, KAl (sub 2) (Si (sub 3) Al)O (sub 10) (OH,F) (sub 2); mica group; pseudohexagonal; perfect basal cleavage; forms large, transparent, strong, electrically and thermally insulating, stable sheets; a common rock-forming mineral in silicic plutonic rocks, mica schists, gneisses, and commercially in pegmatites; also a hydrothermal and weathering product of feldspar and in detrital sediments. Also spelled: moscovite. Syn: isinglass; white mica; potash mica; common mica; Muscovy glass; mirror stone. Sericite is fine-grained muscovite, commonly in connection with hydrothermal alteration, but sericite also includes paragonite and illite. Illite is a common syn. for fine-grained muscovite in clay mineralogy.

Muscovy glass
 * See: muscovite.

mushroom jib
 * A standard form of coal cutter jib with a sprocket at the end remote from the machine. The sprocket carries a vertical turret or bar and is driven by the cutting chain. The bar makes a vertical cut at the back of the normal horizontal cut. See also: turret jib.

muskeg
 * A bog, usually a sphagnum bog, frequently with grassy tussocks, growing in wet, poorly drained boreal regions, often areas of permafrost. Tamarack and black spruce are commonly associated with muskeg areas. Syn: maskeeg.

mussel bed
 * A band containing or chiefly composed of mussellike shells, very valuable in the correlation of Coal Measures strata.

Musso process
 * A mixture of iron ore and fuel is reduced in an externally heated rotary retort. The gases are exhausted and constitute the fuel when the process has been started. The gases, after purification, are passed through combustion rings surrounding the retort and are burned according to the method of catalytic combustion. After reduction, the charge is cooled when it is poured through a layer of fluxing material; it is then transferred to a steelmaking furnace.

mustard gold
 * A spongy type of free gold found in the gossan above gold-silver-telluride deposits.

mutabilite
 * A soft corklike bitumen of porous or resinous consistency. Partly soluble in organic solvents.

muthmannite
 * A mineral, (Ag,Au)Te ; soft; heavy; gray-white; in tabular crystals with perfect cleavage; an ore mineral.

mutu
 * A Malayan term denoting the degrees of fineness of gold.

mutual boundary texture
 * A rock texture showing smooth, regular, curved contacts between minerals.

mvb
 * Abbrev. for medium-volatile bituminous. See also: medium-volatile bituminous coal.

mylonite
 * A compact, chertlike rock without cleavage, but with a streaky or banded structure, produced by the extreme granulation and shearing of rocks that have been pulverized and rolled during overthrusting or intense dynamic metamorphism. Mylonite may also be described as a microbreccia with flow texture. See also: cataclasite; protomylonite; mylonite gneiss; ultramylonite.

mylonite gneiss
 * A mylonitic rock that has been partly recrystallized. See also: augen schist; cataclasite; flaser gabbro; mylonite; phyllonite.

mylonitization
 * Deformation of a rock by extreme microbrecciation, due to mechanical forces applied in a definite direction, without noteworthy chemical reconstitution of granulated minerals. Characteristically the mylonites thus produced have a flinty, banded, or streaked appearance, and undestroyed augen and lenses of the parent rock in a granulated matrix. Also spelled mylonization.

mylonization
 * See: mylonitization.

myrickite
 * a. A white or gray chalcedony, opal, or massive quartz unevenly colored by, or intergrown with, pink or reddish inclusions of cinnabar, the color of which tends to become brown. The opal variety is know as opalite.

b. Cinnabar intergrown with common white opal or translucent chalcedony.

myrmekite
 * An intergrowth of plagioclase feldspar (commonly oligoclase) and vermicular quartz, generally replacing potassium feldspar; formed during the later stages of consolidation in an igneous rock or during a subsequent period of plutonic activity. The quartz occurs as blobs. See: vermicular quartz.

myrmekite antiperthite
 * Myrmekitelike intergrowth of predominant plagioclase and vermicular orthoclase. The wormlike forms of orthoclase are, as a rule, broader than those of quartz in the typical myrmekite.

myrmekite perthite
 * Myrmekitelike intergrowth of microcline and vermicular plagioclase.


text:
अफ़साना

Etymology
, from. .

Noun

 * 1) tale, story

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: अफ़साना


text:
Süßes oder Saures

Interjection

 * 1) trick or treat!

title: Süßes oder Saures


text: creos

title: creos


text:
Appendix:Dictionary of Mining, Mineral, and Related Terms/N/1

N
 * A Diamond Core Drill Manufacturer's Association letter name for a range of diamond drill fittings intended to be used together with the appropriate casing having an inside diameter of 81 mm or somewhat less.

nablock
 * A rounded mass, as of flint in chalk, or of ironstone in coal.

nacre
 * The hard, iridescent internal layer of various mollusk shells, having unusual luster and consisting chiefly of calcium carbonate in the form of aragonite deposited as thin tablets normal to the surface of the shell and interleaved with thin sheets of organic matrix. Syn: pearly; mother-of-pearl.

nacreous
 * Adj. Applied to the luster of certain minerals, usually on crystal faces parallel to a good cleavage, the luster resembling that of pearls.

nacrite
 * A monoclinic mineral, Al (sub 2) Si (sub 2) O (sub 5) (OH) (sub 4) ; kaolinite-serpentine group; differs from other kandites, such as triclinic kaolinite and monoclinic dickite, in the stacking order of its layers (polytypy); fine-grained, massive; commonly associated with hydrothermal alteration.

nadir
 * a. The point on the celestial sphere that is directly beneath the observer and directly opposite the zenith.

b. The point on the ground vertically beneath the perspective center of an aerial-camera lens.

nadorite
 * An orthorhombic mineral, PbSbO (sub 2) Cl ; an uncommon secondary mineral; in resinous to adamantine crystals in some base-metal deposits.

naetig
 * Industrial diamond having a grain in all directions instead of in regular layers. CF: feinig.

nagyagite
 * A possibly orthorhombic mineral, Pb (sub 5) Au(Te,Sb) (sub 4) S (sub 5-8); occurs with other tellurides in lamellar, soft, heavy, lead-gray crystals; one perfect cleavage but may form anhedral masses. Syn: black tellurium.

nahcolite
 * A monoclinic mineral, NaHCO (sub 3) ; forms small, white, highly soluble, prismatic crystals; in nonmarine evaporite deposits; esp. abundant in parts of the Green River lake beds of Colorado.

naif
 * adj. Said of a gemstone having a true or natural luster when uncut; e.g., of the natural, unpolished faces of a diamond crystal. Also spelled naife.

nail
 * a. See: shooting needle.

b. A slender piece of metal, one end of which is pointed, the other end having a head, either flattened or rounded. It is a common means of fastening together several pieces of wood or other material by striking the head with a hammer. The term penny as applied to nails refers to the number of pounds per 1,000 nails; e.g., six-penny nail means 6 lb (2.7 kg) per 1,000; three-penny means 3 lb (1.4 kg) per 1,000, etc.

nailhead spar
 * A composite variety of calcite having the form suggested by the name.

naked
 * See: bare; blank hole.

name of lode
 * The name by which a lode is designated in the notice of location, and subsequent addition thereto is immaterial. The same vein or lode may have different names in different mining locations.

nanotesla
 * See: gamma.

Nansen bottle
 * An oceanographic water-sampling bottle, made of a metal alloy that is little reactive with seawater, equipped with a rotary valve at each end so that when it is rotated at depth the valves close and lock shut, entrapping a water sample and setting the reversing thermometers. This bottle is named for its designer, Fridtjof Nansen.

nantokite
 * An isometric mineral, CuCl ; granular, massive; cubic cleavage; adamantine luster; an uncommon secondary mineral in copper deposits.

naphtha
 * a. An archaic term for liquid petroleum.

b. Designates those hydrocarbons of the lowest boiling point (under 250 degrees C) that are liquid at standard conditions, but easily vaporize and become flammable. They are used as cleaners and solvents.

naphtha gas
 * Illuminating gas charged with the decomposed vapor of naphtha.

naphthode
 * Concretion of bituminous limestone rich in carbonaceous matter.

Napierian logarithm
 * A natural logarithm.

napoleonite
 * A variety of hornblende.

nappe
 * a. A sheetlike, allochthonous rock unit, which has moved on a predominantly horizontal surface. The mechanism may be thrust faulting, recumbent folding, or both. The term was first used for the large allochthonous sheets of the western Alps, and it has been adopted into English. The German equivalent, decke, is also sometimes used in English. Etymol: French, cover sheet, tablecloth. Syn: decke. See also: klippe.

b. Belg. See: aquifer.

napthoid
 * Liquid petroleumlike product found in cavities of igneous rocks and assumed to be a product of thermal distillation of bituminous substances contained in the country rocks.

narrow
 * a. A roadway driven in the solid coal with rib sides. All roadways when opening out a pillar method of working are narrow. See also: working the whole.

b. N. of Eng. A gallery, or roadway, driven at right angles to a drift, and not quite so large in area.

narrow gage
 * A railway gage narrower than the standard gage of 4 ft 8-1/2 in (1.44 m).

narrow place
 * Aust. Working place that is less than 6 yd (5.5 m) wide; these are paid for by the yard in length.

narrow stall
 * A stall driven in solid coal, usually from 6 to 9 ft (1.8 to 2.7 m) wide; it has rib sides in coal. See also: rib-side; solid road.

narrow work
 * a. The driving of narrow stalls to form coal pillars as the first stage in the pillar-and-stall method of working.

b. A system of mining in which narrow coal roadways, called endings, are driven along the strike of the seam, from 12 to 15 yd (11.0 to 13.7 m) apart, to a limit line. The long narrow coal pillars between the endings are extracted on the retreat. It has been adopted in parts of Yorkshire and Lancashire, England. See also: endings; main endings. c. All work for which a price per yard of length driven is paid, and which, therefore, must be measured. Any dead work. d. Penn. Headings, chutes, crosscuts, gangways, etc., or the workings previous to the removal of the pillars. e. A working place in coal only a few yards in width.

narrow working
 * See: bord-and-pillar method; narrow work.

nascent
 * Just formed by a chemical reaction, and therefore very reactive. Nascent gases are probably in an atomic state.

Nasmyth hammer
 * A steam hammer, having the head attached to the piston rod, and operated by the direct force of the steam.

Na-spar
 * See: soda spar.

National coarse thread
 * The screw thread of common use, formerly known as the United States Standard thread.

National Electrical Code
 * A set of rules to guide electricians when installing electrical conductors, devices, and machinery.

national grid
 * Gr. Brit. A system of rectangular coordinates used by the Ordnance Survey and based upon the Transverse Mercator Projection (which is also known as the Gauss Conformal Projection).

national grid coordinates
 * Gr. Brit. Coordinates, referred to the National Grid of the Ordnance Survey, which are specified in meters and consist of two components, an Easting and a Northing.

Nationalization Act
 * The Coal Industry Nationalization Act, 1946, which brought all coal mines in the United Kingdom under public ownership. It was passed through Parliament in JuIy 1946 and put into operation on January 1, 1947.

National Physical Laboratory
 * British government organization that, among other things, tests and certifies calibration of scientific glassware, weights, and measures. Abbrev. NPL.

native
 * a. Occurring in nature, either pure or uncombined with other substances. Usually applied to metals, such as native mercury, native copper. Also used to describe any mineral occurring in nature in distinction from the corresponding substance formed artificially.

b. Adj. Applied to earth materials occurring in elemental form; e.g., nugget gold, metallic copper. Syn: native element.

native copper
 * a. Metallic copper, sometimes containing a little silver and bismuth, that occurs as a metasomatic deposit filling cracks and forming the cement of sandstone and conglomerate. Such deposits have been found in the Keweenaw Peninsula, Lake Superior, MI, USA; Chile; Queensland, Australia; and Zimbabwe. Native copper is also found in the upper workings of copper mines.

b. A mineral in the form of particles and nuggets of very pure metallic copper associated (but not alloyed) with small amounts of silver and arsenic minerals. It is found in small amounts in many copper ores but occurs in commerical quantities in only one place in the world, the Upper Peninsula in Michigan. See also: copper.

native element
 * Element that occurs in nature uncombined, such as nugget gold, metallic copper, etc. See also: native.

native mercury
 * See: quicksilver.

native nickel-iron
 * See: awaruite; josephinite.

native water
 * See: formation water.

natrite
 * A monoclinic mineral, NaCO (sub 3) ; occurs in very soluble, white, granular masses; a rare mineral in the alkalic complexes of the Kola peninsula, Russia.

natrium
 * See: sodium.

natrochalcite
 * A monoclinic mineral, NaCu (sub 2) (SO (sub 4) ) (sub 2) (OH).H (sub 2) O; bright emerald-green; forms steep pyramidal crystals; a secondary copper mineral at Chuquicamata, Chile.

natrojarosite
 * A trigonal mineral, NaFe (super 3+) (sub 3) (SO (sub 4) ) (sub 2) (OH) (sub 6) ; alunite group; in earthy masses and minute scales; a common alteration product in pyrite-bearing deposits. Formerly called utahite.

natrolite
 * ].16H (sub 2) O ; zeolite group, which may contain appreciable calcium; dimorphous with tetranatrolite; forms acicular to slender prismatic crystals in cavities and veins, esp. in mafic and alkaline igneous rocks. Syn: laubanite.

natromontebrasite
 * A triclinic mineral, (Na,Li)Al(PO (sub 4) )(OH,F) ; amblygonite group; in granitic pegmatites associated with other lithium minerals. Formerly called fremontite.

natron
 * A monoclinic mineral, Na (sub 2) CO (sub 3) .10H (sub 2) O ; very soluble; forms earthy or granular crusts and efflorescences; in nonmarine evaporites and on lavas.

natrona
 * See: sodium sesquicarbonate.

natron granite
 * Granite abormally high in soda, presumably from the presence of a soda-rich orthoclase or of anorthoclase. It is also called soda granite.

nattle
 * Eng. To make a slight rattling or tapping noise. Said of a mine when movement or settling is taking place.

natural air crossing
 * An air crossing in which two airways are separated by rock in its natural state.

natural asphalt
 * Asphalt before crushing or refining, as mined or quarried in the case of natural rock asphalt, or surface-excavated in the case of lake deposits.

natural carbon
 * Carbon found in a shape that has not been artificially modified. Also called natural stone.

natural cement
 * A hydraulic cement produced by pulverizing and then heating naturally occurring rock (cement rock) containing appropriate proportions of limestone, clay, magnesia, and iron. Ignition temperatures are usually lower than for portland cement. Final pulverizing is necessary as with portland cement.

natural coke
 * Coke made by natural processes, usually by the intrusion of an igneous dike. See also: cinder coal; clinker; coke coal; cokeite.

natural convection
 * See: convection.

natural diamond
 * This abrasive is the densest form of crystallized carbon, the hardest substance known. It occurs most commonly as well-developed crystals in volcanic pipes or in alluvial deposits. Bort (boart or borts) sometimes refers to all diamonds not suitable for gems, or it may refer to off-color, flawed, or impure diamonds not fit for use for gems or most other industrial applications, but suitable for the preparation of diamond grain and powder for use in lapping or the manufacture of most diamond grinding wheels. This type of bort is also called crushing bort or fragmented bort.

natural Earth current
 * Electric current in the Earth not due to human activity.

natural face
 * A name given to the X direction as pencilled on Z sections of unfaced quartz and whose position is determined by X-ray measurements or etching. The name is also given to the artificial prism face (parallel to 1120) thus located, and produced by sawing the section in the YZ plane. Also applied to the natural growth faces on faced raw quartz crystals.

natural floatability
 * See: inherent floatability.

natural frequency
 * The frequency of free oscillation of a system. For a multiple-degree-of-freedom system, the natural frequencies are the frequencies of the normal modes of vibration.

natural frequency of a foundation
 * The frequency of free vibration of a complete soil-foundation oscillating system. This frequency must differ distinctly from that of any machinery carried by the foundation if resonance is to be avoided.

natural frequency vibrating conveyor
 * A vibrating conveyor in which the rate of free vibration of the trough on its resilient supports is approx. the same as the rate of vibration induced by the driving mechanism.

natural gamma radiation detector
 * This is a type of sensor that measures bursts of high-energy electromagnetic waves that are emitted spontaneously by some naturally occurring radioactive elements, such as potassium-40, thorium-232, and uranium-238, that are commonly present in shales and clays.

natural gamma-ray logging
 * A process whereby gamma rays naturally emitted by formations traversed by a borehole are measured. A tool containing a radiation detector is lowered into the borehole and gamma ray measurements are transmitted to the Earth's surface. The signals are utilized to produce a record of gamma rays detected in correlation with the depth of the detector in the borehole. The record thus obtained in the form of a curve indicating relative number per unit of time of natural gamma rays at different depths, is a conventional natural gamma-ray log, sometimes simply called a gamma-ray log.

natural gas
 * A mixture of the low-molecular-weight paraffin series hydrocarbons methane, ethane, propane, and butane, with small amounts of higher hydrocarbons; also frequently containing small or large proportions of nitrogen, carbon dioxide, and hydrogen sulfide, and occasionally small proportions of helium. Methane is almost always the major constituent. Natural gas accompanying petroleum always contains appreciable quantities of ethane, propane, butane, as well as some pentane and hexane vapors, and is known as wet gas. Dry gas contains little of these higher hydrocarbons. The exact composition of natural gas varies with locality. The heating value of natural gas is usually over 1,000 Btu/ft (super 3) unless nitrogen or carbon dioxide are important components of the gas. See also: gas; sour gas.

natural glass
 * A vitreous, amorphous, inorganic substance that has solidified from magma too quickly to crystallize. Granitic or acid natural glass includes pumice and obsidian; an example of a basaltic natural glass is tachylite.

natural logarithm
 * A logarithm with e as a base.

naturally bonded molding sand
 * A term used by foundrymen to refer to a sand that, as mined, contains sufficient bonding material for molding purposes.

natural ore
 * a. In iron mining, the term given to naturally occurring high-grade iron ore; consists of: (1) soft ore, such as porous hematite and limonite (goethite) with minor magnetite and manganese oxides; and (2) hard ores, such as compact, fine-grained, steel-gray hematite, specular hematite, magnetite, or martite. Syn: direct shipping ore.

b. Iron ore that contains moisture, in contrast to "dry ore" that has been dried but not calcined. c. A term used in the U.S. Lake Superior mining district to indicate iron ore formed by natural processes, as distinguished from iron ore products (such as pellets) produced artificially from hard, low-grade ores of the taconite type. Published prices for natural ores from this district usually specify iron content as "natural," meaning that the analysis is based on gross weight including moisture. Syn: lump ore; silicious ore; high-silica ore; wash ore; heavy-media ore; manganiferous ore; natural ore concentrate; lean ore; paint-rock ore; Mesabi non-Bessemer ore.

natural ore concentrate
 * See: natural ore.

natural paper
 * Brownish paperlike deposit formed from the filaments of Conferva.

natural resin
 * See: resin.

natural sand
 * Sand derived from a rock, in which the grains separate along their natural boundaries. This includes unconsolidated sand or a soft sandstone where little pressure is required to separate the individual grains.

natural scale
 * Applied to a drawing made to equal vertical and horizontal scales.

natural slope
 * The maximum angle at which loose material in a bank or spoil heap will stand without slipping. See also: angle of rest; angle of slide.

natural splitting
 * In mine ventilation, a practice that allows the airflow to divide among the branches of its own accord and without regulation, in inverse relation to the resistance of each airway. CF: controlled splitting.

natural stress relief
 * The failure of the skin rock of an excavation by crushing, shear, or plastic flow. It can occur on free surface rock with explosive force. See also: arching.

natural ventilating pressure
 * a. In a mine, air returning from the workings to the surface via the upcast shaft can be of a higher temperature than the air in the downcast shaft because of heat added to the ventilation current from the strata exposed in the mine. Thus, even in a mine with the fan stopped, the upcast air density is less than the downcast air density. This lack of balance in the two vertical air columns produces a pressure difference across the shaft bottom doors known as natural ventilating pressure.

b. The ventilating pressure that produces natural ventilation.

natural ventilation
 * The ventilation produced in a mine as a result of a difference in density of the air in the upcast and downcast shafts, brought about by natural causes. Natural ventilation is feeble, seasonal, and inconstant.

nauckite
 * A variety of resin.

naumannite
 * An orthorhombic mineral, Ag (sub 2) Se ; pseudocubic; black; lustrous; forms heavy, sectile granular masses; also in thin plates; epithermal; a major source of silver in some deposits.

nautical chart
 * A representation on a horizontal plane, and according to a definite system of projection, of a portion of the navigable waters of the Earth, including the shorelines, the topography of the bottom, and aids and dangers to navigation; it may be derived from hydrographic, topographic, or aerial surveys, or a combination thereof.

nautical measure
 * One nautical mile or knot equals 6,080.20 ft (1,853.248 m); 3 nmi equal 1 league; and 60 nmi equal 1 degree of longitude (at the equator).

nautical mile
 * Any of various units of distance, used for sea and air navigation, based on the length of a minute of arc of a great circle of the Earth and differing because the Earth is not a perfect sphere: (1) a British unit that equals 6,080 ft or 1,853.2 m; also called Admiralty mile; (2) a U.S. unit, no longer in official use, that equals 6080.20 ft or 1,853.248 m; and (3) an international unit that equals 6,076.1033 ft or 1,852 m; used officially in the United States since July 1954.

navajoite
 * A monoclinic mineral, (V,Fe) (sub 10) O (sub 24) .12H (sub 2) O ; rare; weakly radioactive; soft; a fibrous mineral with a silky luster; associated with corvusite, hewettite, tyuyamunite, rauvite, steigerite, and limonite.

Navier's hypothesis
 * An assumption in the design calculation of beams. It states that the stress at any point due to bending is assumed as being proportional to its distance from the neutral axis.

NCB
 * The National Coal Board of the United Kingdom.

NCB boring tower
 * A boring tower developed by the National Coal Board of the United Kingdom to make test drillings for coal from positions off the coast. When drilling is in progress, the tower is resting on the seabed. The base is divided into four airtight sections, which are filled with water when the tower is in position for drilling. The water is pumped out to give buoyancy when the tower is refloated for towing to a new drilling site. The tower is designed to withstand gales of 80 mph (128 km/h) and waves of 30 ft (9.1 m) from crest to trough, and it can be used in any depth of water up to 120 ft (36.6 m). The overall height of the tower is 189 ft (57.6 m), and its total weight is about 570 st (517 t). It has reached over 3,000 ft (915 m) drilling depth with core recovery. The first borehole was put down in the Firth of Forth, Scotland.

NCB recorder
 * This butane combustible gases recorder has a small flame of burning butane gas, which is controlled to give constant heat output with varying ambient temperature and humidity, and with varying butane gas pressure. The heat output is measured by means of a group of thermocouples in a chimney above the flame. The presence of methane in the atmosphere, which has access to the flame via suitable gauzes, increases the voltage generated by the thermocouples. These changes are recorded on a rotating chart calibrated in percentage methane.

neap tide
 * In oceanography, a high tide occurring at the moon's first or third quarter, when the sun's tidal influence is working against the moon's, so that the height of the tide is below the maximum in the approximate ratio of 3:8.

nearest neighbor interpolation method
 * A method of assigning a sample value to a point in space. The value assigned is equal to the value of the spatially nearest sample data point. This method is sometimes used as a computer equivalent of the polygonal method of interpolation.

near-gravity material
 * A washability term popularly defined as the percentage of material in the raw coal within + or -0.1 of the separating specific gravity.

near-mesh
 * Near-sized; grains close in cross section to a specified screening mesh, which tend to blind apertures and slow down sizing. Syn: near-mesh material.

near-mesh material
 * Material approximating in size to the mesh aperture.

neat
 * Cement slurries containing no aggregate, such as sand or gravel. Syn: neat cement.

neat cement
 * A slurry composed of any cement and water. Syn: neat cement.

neat lines
 * The excavation lines of a tunnel within which the rock removed is paid for at the agreed contract rate. See also: overbreak.

nebulite
 * A type of mixed rock whose fabric is characterized by indistinct, streaky inhomogeneities or schlieren and in which no sharp distinction can be made between the component parts of the fabric. Adj: nebulitic.

neck
 * a. A lava-filled conduit of an extinct volcano exposed by erosion; also called chimney rock or plug. See also: plug.

b. A pipe of igneous rock crossing bedding planes. c. The narrow entrance to a room next to the entry, or a place where the room has been narrowed on account of poor roof. d. A narrow stretch of land, such as an isthmus or a cape. e. A narrow body of water between two larger bodies; a strait.

needle
 * a. A piece of copper or brass about 0.5 in (1.3 cm) in diameter and 3 ft or 4 ft (0.9 m to 1.2 m) long, pointed at one end, and turned into a handle at the other, tapering from the handle to the point. It is thrust into a charge of blasting powder in a borehole, and while in this position the borehole is tamped solid, preferably with moist clay. The needle is then withdrawn carefully, leaving a straight passageway through the tamping for the miner's squib to shoot or fire the charge.

b. A timber set on end to close an opening for the control of water; it may be either vertical or inclined; a form of stop plank. c. A small metal rod for making the touchhole in the powder used for blasting. d. A hitch cut in the side rock to receive the end of a timber. e. A needle-shaped or acicular mineral crystal.

needle bearing
 * An antifriction bearing using very small-diameter rollers between wide faces.

needled
 * Pocketed, as when face bars are set with the face end of the bar pocketed into the coal adjacent to the roof.

needle instrument
 * Any surveying instrument controlled by a magnetic needle. See also: compass.

needle ore
 * a. Iron ore of very high metallic luster, found in small quantities, which may be separated into long, slender filaments resembling needles.

b. See: aikinite.

needles
 * Elongated crystals, tapering at each end to a fine point, as those typical of martensite.

needle traverse
 * In a survey with a dial (compass), use of a magnetic needle to read the bearing of lines. Opposite is fast needle traverse or work, and refers to the use of a dial as in traversing with a theodolite, where proximity of iron might deflect the needle. Systems can be combined, using needle readings where iron is absent. Also called swinging needle traverse; loose needle traverse.

negative crystal
 * a. A birefringent crystal in which the refractive index of the extraordinary ray is less than that of the ordinary ray.

b. A cavity within a crystal bounded by the crystal faces of that crystal. See also: inclusion; three-phase inclusion.

negative element
 * A large structural feature or portion of the Earth's crust, characterized through a long period of geologic time by frequent and conspicuous downward movement (subsidence, submergence), extensive erosion, or an uplift that is considerably less rapid or less frequent than those of adjacent positive elements.

negative elongation
 * Lathlike, rodlike, or acicular crystals in which the slow polarized light ray lies across the long direction of the crystal. CF: positive elongation. Syn: length fast.

negative moment
 * See: hogging moment.

negative rake
 * a. The orientation of a cutting tool in such a manner that the angle formed by the leading face of the tool and the surface behind the cutting edge is greater than 90 degrees . Syn: drag rake. See also: gouge angle.

b. Describes a tooth face in rotation whose cutting edge lags the surface of the tooth face. CF: rake.

negligence
 * In a legal sense, a failure upon the part of a mine operator to observe for the protection of the interests of the miner that degree of care, precaution, and vigilance that the circumstances justly demand, whereby the miner suffers injury.

neighborite
 * An orthorhombic mineral, NaMgF (sub 3) ; insoluble; forms rounded grains or pseudo-octahedral crystals; associated with dolomite and quartz in oil shale within the Green River Formation, UT.

nekton
 * A biological division made up of all the swimming animals found in the pelagic division.

Nelson Davis separator
 * A cylindrical dense-medium washer developed in the United States. It uses a magnetite water suspension as medium. The bath resembles a drum in shape, its longitudinal axis being horizontal; within the stationary outer casing there is a rotor divided into compartments. Raw coal is fed near the top of the separator, and separation takes place as the rotor revolves. The machine produces clean coal and shale; the magnetite is recovered. It can handle coal up to 10 in (254 mm) in size, the lower limit being about 1/4 in (6.4 mm). Magnetite consumption runs at about 1/2 lb/st (0.25 kg/t) of feed. See also: Leebar separator.

nelsonite
 * A rock composed essentially of ilmenite and apatite, with or without rutile. The ratio of ilmenite to apatite varies widely. CF: ilmenitite.

nematoblastic
 * Pertaining to the texture of a recrystallized rock in which the shape of the grains is threadlike. See also: fibroblastic.

neokerogen
 * Organic debris deposited among marine sediments and modified by bacterial action in such a way as to form the source material of petroleum, or, under certain conditions, to form the kerogen of oil shales.

neolite
 * A silky, fibrous, stellated, green, hydrous magnesium-aluminum silicate.

Neolithic
 * In archaeology, the last division of the Stone Age, characterized by the development of agriculture and the domestication of farm animals. Correlation of relative cultural levels with actual age (and, therefore, with the time-stratigraphic units of geology) varies from region to region. Adj: pertaining to the Neolithic.

neomesselite
 * See: messelite.

neomineralization
 * Chemical interchange within a rock whereby its mineral constituents are converted into new mineral species; a type of recrystallization.

neomorphic
 * Said of the mineral grains of a rock that have been regenerated by zones of secondary growth in crystalline continuity. The new material may have been deposited from solutions or from molten fluids.

neoprene plug closure
 * The function of the neoprene plug is to provide a completely waterproof seal at the open end of the detonator. Moisture penetration could cause desensitization of the explosive charge in the detonator, and in the case of copper-tubed detonators, moisture could produce a potentially dangerous chemical reaction between the lead azide and the copper.

nepheline
 * A hexagonal mineral, (Na,K)AlSiO (sub 4) ; feldspathoid group; greasy luster; forms glassy crystals, colorless grains, coarse crystals with prismatic cleavage, or masses without cleavage; occurs in alkalic igneous rocks; an essential constituent of some sodium-rich rocks, e.g., nepheline syenite. Formerly called nephelite; eleolite.

nepheline syenite
 * A plutonic rock composed essentially of alkali feldspar and nepheline. It may contain an alkali ferromagnesian mineral, such as an amphibole (riebeckite, arfvedsonite, barkevikite) or a pyroxene (acmite or acmite-augite); the intrusive equivalent of phonolite. Sodalite, cancrinite, hauyne, and nosean, in addition to apatite, sphene, and opaque oxides, are common accessories. Rare minerals are also frequent accessories. Syn: foyaite; eleolite syenite; midalkalite.

nephelinite
 * A fine-grained or porphyritic extrusive or hypabyssal rock, of basaltic character, but primarily composed of nepheline and clinopyroxene, esp. titanaugite, and lacking olivine and feldspar.

nephelinitoid
 * A nepheline-rich groundmass in an igneous rock; the glassy groundmass in nepheline rocks.

nephelinization
 * The process of introduction of or replacement by nepheline.

nephelometry
 * The measurement of the cloudiness of a medium; esp. the determination of the concentration or particle sizes of a suspension by measuring, at more than one angle, the scattering of light transmitted or reflected by the medium. CF: turbidimetry.

nephrite
 * An exceptionally tough, compact, fine-grained, greenish or bluish variety of amphibole (specif. tremolite or actinolite) constituting the less rare or valuable kind of jade. Syn: kidney stone; greenstone.

neptunian dike
 * A dike filled by sediment, generally sand, in contrast to a plutonic dike filled by volcanic materials. See also: sand dike.

neptunian theory
 * See: neptunism.

neptunism
 * The theory, advocated by A. G. Werner in the 18th century, that the rocks of the Earth's crust all consist of material deposited sequentially from, or crystallized out of, water. Etymol: Neptune, Roman god of waters. CF: plutonism. Syn: neptunian theory.

neptunite
 * A monoclinic mineral, KNa (sub 2) Li(Fe,Mn) (sub 2) Ti (sub 2) Si (sub 8) O (sub 24) ; forms red to black prismatic crystals; occurs in late stages of reduced, silica-deficient environments; e.g., alkaline igneous rocks and veins in serpentinite. See also: mangan-neptunite.

neritic
 * Pertaining to the shallow seas; for accumulations of shells, but sometimes for the whole environment of deposition on the continental shelf.

neritic zone
 * That part of the sea floor extending from the low tide line to a depth of 200 m.

Nernst film
 * In ion exchange, the diffusion-layer supposed to surround a bead of resin. This static film is reduced, or diffusion through it is accelerated, if agitation of the ambient liquor is increased, if temperature is raised, or if concentration of ions in solution is made greater.

nero-antico
 * A black marble found in Roman ruins, probably from the Taenarian peninsula, Greece.

nesquehonite
 * An orthorhombic mineral, Mg(HCO (sub 3) )(OH).2H (sub 2) O ; forms low-temperature efflorescences, particularly as an alteration product of lansfordite. Named for a coal mine at Nesquehoning, PA.

ness
 * A British term used esp. in Scotland for a promontory, headland, or cape, or any point or projection of the land into the sea; commonly used as a suffix to a place name, e.g., Fifeness. Also called nose.

nest
 * a. A concentration of some relatively conspicuous element of a geologic feature, such as a nest of inclusions in an igneous rock or a small, pocketlike mass of ore or mineral within another formation.

b. A fitting of the next-smaller-size casing inside the casing already set in a borehole, or of one tube inside another.

nested variogram model
 * A model that is the sum of two or more component models, such as nugget, spherical, etc. Adding a nugget component to one of the other models is the most common nested model, but more complex combinations are occasionally used.

net
 * a. Scot. Strapping used for lowering or raising horses in shafts.

b. A plane of points each with identical point surroundings. CF: space lattice; lattice.

net calorific value
 * The heat produced by combustion of unit quantity of a solid or liquid fuel when burned, at a constant pressure of 1 atm (0.1 MPa), under conditions such that all the water in the products remains in the form of vapor. Net heat of combustion at constant pressure is expressed as Q (sub p) (net).

net-corrected fill
 * Net fill after making allowance for shrinkage during compaction.

net drilling time
 * The amount of excavated material to be removed from a road section, after completing fills in that section. �@  A�U ��U �<� �       � e DICTIONARY TERMS:net drilling time The rotating time actually spent The rotating time actually spent in deepening a borehole.

net fill
 * The fill required, less the cut required, at a particular station or part of a road.

nether
 * The lower part of, as in nether roof; opposite of the term "upper."

nether roof
 * a. The strata directly over a coal seam. The props set at the face hold only the nether roof. E.g., if the props carry a load of 20 st (18.1 mt) each and are set 4 ft (1.2 m) apart each way, the supported weight is 1.5 st/ft (super 2) (14.6 t/m (super 2) ). See also: underweight; absolute roof; overarching weight; immediate roof.

b. In mine subsidence, the immediate roof of limited depth, such as timber might be expected to support.

nether strata
 * The roof and strata immediately above the coal.

net slip
 * On a fault, the distance between two formerly adjacent points on either side of the fault, measured on the fault surface or parallel to it. It defines both the direction and relative amount of displacement.

net texture
 * See: network structure.

Nettleton method
 * An indirect means of density determination in which a closely spaced gravity traverse is run over some topographic feature, such as a small hill or valley. When the profile of observed values is plotted, the gravitational effect of the feature itself is calculated at each observation point along the profile and removed from the observed value for that point. The calculation is repeated a number of times, different densities being assumed for each computation. The density value at which the hill is least conspicuous on the gravity profile is considered to be most nearly correct.

net unit value
 * The difference between the gross unit recoverable value and the cost of mining, treating, and marketing ore; in other words, the net operating profit. See also: gross recoverable value; gross unit value.

network
 * a. Esp. in surveying and gravity prospecting, a pattern or configuration of stations, often so arranged as to provide a check on the consistency of the measured values.

b. In ventilation surveys, the multiple development openings, haulage ways, and working faces that constitute the ventilation system of a mine.

network deposit
 * See: stockwork.

network structure
 * A structure in which one constituent occurs primarily at the grain boundaries, thus partially or completely enveloping the grains of the other constituent. Syn: net texture.

Neuenburg saw
 * A plow consisting of a 2-in (5.1-cm) steel plate 6 ft by 20 in (1.8 m by 50.8 cm) of seven pieces hinged together to follow floor rolls; picks on the face edge cut in both directions. The minimum workable seam is 14 in (35.6 cm) on gradients of 35 degrees to 70 degrees . Maximum face length is 80 yd (73.2 m). The machine is used in the Ruhr.

neuk
 * The tailgate corner of a face behind the face conveyor tension end.

Neumann lamellae
 * Straight, narrow bands parallel to the crystallographic planes in the crystals of metals that have been subjected to deformation by sudden impact. They are actually narrow twin band, and are most frequently observed in iron.

neuropteris
 * A large tree-fern of the coal forest, with trunks about 2 ft (0.6 m) thick, containing several cylinders of wood inside the stem instead of one column of wood as in modern trees.

neutral atmosphere
 * Atmosphere in which there is neither an excess nor a deficiency of oxygen.

neutral axis
 * The line of zero fiber stress in any given section of a member subject to bending; it is the line formed by the intersection of the neutral surface and the section.

neutral equilibrium
 * A body is said to be in neutral equilibrium if on being slightly displaced it remains in its new position; e.g., a ball placed on a horizontal surface or a cone supported on its side on a horizontal surface.

neutralize
 * To add either an acid or alkali to a solution until it is neither acid nor alkaline.

neutral lining
 * Furnace lining of neutral refractories.

neutral point
 * a. A neutral point in a wye-connected alternating-current power system means the connection point of transformer or generator windings from which the voltage to ground is nominally zero, and which is the point generally used for system grounding.

b. In titration, the point at which hydrogen ions and hydroxyls are approx. balanced, each at about 1 times 10 (super -7) molar. Since color-change-indicating dyes do not all react at this point, selection for a given titration must be made with regard to the required point of change.

neutral pressure
 * The hydrostatic pressure of the water in the pore space of a soil. See also: pore-water pressure; pore pressure; neutral stress.

neutral refractory
 * a. A refractory that is neither strongly basic nor strongly acid, such as chrome, mullite, or carbon.

b. A refractory that is resistant to chemical attack by both acid and basic slags, refractories, or fluxes at high temperatures.

neutral salt
 * A salt in which all the hydrogen of the hydroxyl groups of an acid is replaced by a metal.

neutral salt effect
 * Reduction of ionization of a weak acid or base by addition of ionizing salt that contains one of the ions already present; form of common ion effect.

neutral stress
 * The stress transmitted by the fluid that fills the voids between particles of a soil or rock mass; e.g., that part of the total normal stress in a saturated soil caused by the presence of interstitial water. Syn: pore pressure; pore-water pressure; neutral pressure.

neutral surface
 * The longitudinal surface of zero fiber stress in a member subject to bending; it contains the neutral axis of every section.

neutral zone
 * A strain-free area. CF: compression zone; tension zone.

neutron
 * An uncharged elementary particle with a mass that nearly equals that of the proton. An isolated neutron is unstable and decays with a half-life of about 13 min into an electron, a proton, and a neutrino. Neutrons sustain the fission chain reaction in a nuclear reactor.

neutron density
 * The number of neutrons per cubic centimeter.

neutron-gamma log
 * A radioactivity log employing both gamma and neutron-log curves. The neutron log should respond best to porous fluid-filled rock and the gamma best to shale markers.

neutron log
 * Strip recording of the secondary radioactivity arising from the bombardment of the rocks around a borehole by neutrons from a source being caused to move through the borehole. Used, generally in conjunction with other types of logs, for the identification of the fluid-bearing zones of rocks. See also: radioactivity log; neutron logging.

neutron logging
 * A radioactivity logging method used in boreholes in which a neutron source provides neutrons that enter rock formations and induce additional gamma radiation, which is measured by use of an ionization chamber. The gamma radiation so induced is related to the hydrogen content of the rock.

Nevadan orogeny
 * Late Jurassic-Early Cretaceous diastrophism in Western North America.

nevyanskite
 * A former name for iridosmine. See also: iridosmine.

Newark Supergroup
 * Continental strata of Lower Jurassic or Upper Triassic age in the Eastern United States, consisting essentially of red sandstone, shale, arkose, and conglomerate, some 14,000 to 18,000 ft (4.3 to 5.5 km) thick. The series includes black shales with fish remains, thin coal seams in Virginia and North Carolina, and basaltic flows and sills.

Newaygo screen
 * A slanting screen in which the material to be screened passes down. The screen is kept in vibration by the impact of a large number of small hammers.

newjersite
 * Variety of resin.

Newlyn datum
 * The mean sea level now used as the British Ordnance Datum for leveling. It was determined as the result of several years' observations at Newlyn, Cornwall, England, and differs at various places by more than 0.3 m from levels based on the Liverpool datum, which it supersedes.

Newmann hearth
 * A modified Scotch hearth in which poking or rabbling is done mechanically.

new miner training
 * In mining, mandatory training given the miners having no previous mining experience; includes instruction in the statutory rights of miners and their representatives, use of self-rescue devices and respiratory devices where appropriate, hazard recognition, emergency procedures, electrical hazards, first aid, walk around training, and other health and safety aspects of the tasks to which the person will be assigned. CF: refresher training; task training.

new sand
 * Newly mixed, but not unused, molders' sand.

new scrap
 * The material generated in the manufacturing process of articles for ultimate consumption; it includes defective castings, clippings, turnings, borings, drosses, slags, etc., that are returned directly to the manufacturing process or sold directly for reprocessing.

Newtonian fluid
 * Term marking the distinction, made in mineral processing that involves agitation, between a truly viscous (Newtonian) liquid and one in which shear or apparent viscosity (pseudoviscosity) varies with the dimensions of the containing system and the speed of agitation. The latter type of fluid is said to be non-Newtonian.

Newton's law of gravitation
 * See: law of gravitation.

New York rod
 * A leveling rod marked with narrow lines, ruler fashion.

N-frame brace
 * A diagonal brace in a square set.

ngavite
 * A chondritic stony meteorite composed of bronzite and olivine in a friable, breccialike mass of chondrules.

niccolite
 * A former name for nickeline. Also spelled nicolite. Syn: arsenical nickel; copper nickel.

Nicholls' technique
 * A technique used in the determination of elastic constants of rock in situ. Longitudinal and shear waves are generated in rock by small explosive charges in shallow drill holes. Accelerometers and strain gages are employed to measure arrival times for both waves. From wave velocities and measured density, Poisson's ratio, modulus of elasticity, modulus of rigidity, Lame's constant, and bulk modulus can be calculated.

nickel
 * a. An isometric mineral, elemental Ni; hard; metallic; silver-white; a native metal, esp. in meteorites; also alloyed with iron in meteorites.

b. A silvery white, hard, malleable, ductile, somewhat ferromagnetic element. Symbol: Ni. It takes on a high polish and is a fair conductor of heat and electricity. Used for making stainless steel and other corrosion-resistant metals and is chiefly valuable for the alloys it forms. Also used extensively in coinage, in desalination plants for converting sea water into fresh water, and in making nickel steel for armor plate and burglar-proof vaults.

nickel antimony glance
 * Sulfantimonide of nickel, crystallizing in the cubic system. Also called ullmannite.

nickel bloom
 * A green hydrated and oxidized patina on rock outcrops indicating the existence of primary nickel minerals; specif. annabergite (a nickel arsenate). The term is also applied to zaratite (a nickel carbonate) and to morenosite (a nickel sulfate). See also: annabergite.

nickel carbonyl
 * A volatile compound of nickel, Ni(CO) (sub 4), formed by passing carbon monoxide over the heated metal. The compound is decomposed into nickel and carbon monoxide by further heating. It is used on a large scale in industry for the production of nickel from its ores by the Mond process.

nickel glance
 * See: gersdorffite.

nickel green
 * See: annabergite.

nickeliferous
 * Containing nickel.

nickeline
 * a. A hexagonal mineral, 2[NiAs] ; commonly contains antimony, cobalt, iron, and sulfur; one of the chief ores of nickel. Formerly called: niccolite; nickelite; arsenical nickel; copper nickel; kupfernickel.

b. The mineral group breithauptite, freboldite, imgreite, langisite, nickeline, sederholmite, sobolevskite, stempflite, and sudburyite.

nickel iron
 * a. A mineral, NiFe, containing about 76% nickel and found in meteorites. Isometric.

b. The native alloy of nickel with iron in meteorites. See also: kamacite; taenite.

nickelite
 * A former name for nickeline. See also: nickeline.

nickel ocher
 * An early name for annabergite.

nickelous oxide
 * a. NiO; green, becoming yellow. Found in nature as the mineral bunsenite. Soluble in acids and in ammonium hydroxide; insoluble in water; sp gr, 6.6 to 6.8. NiO absorbs oxygen at 400 degrees C forming Ni (sub 2) O (sub 3) which is reduced to NiO at 600 degrees C. Used in nickel salts and in porcelain painting.

b. Isometric; green to black; molecular weight, 74.71; melting point, 1,990 degrees C; sp gr, 6.67. Used for painting on china.

nickel oxide
 * Comprises the two nickel oxides, nickelous oxide (NiO) and nickelic oxide (Ni (sub 2) O (sub 3) ), which are used extensively as colorants in glasses, glazes, and enamels. The use of nickel oxide in enamels is generally in the ground coat, in which it is used with cobalt and manganese. It is also used in cover coat enamels to give what is known as a daylight shade for reflector units. Nickelic oxide imparts a color to glass which is dependent upon the character of the alkali present. Nickelous oxide is used in glazes to produce blues, greens, browns, and yellows. Nickel oxide is also one of the principal components of certain type of ferrites, e.g, the nickel-zinc ferrite. See also: nickelous oxide.

nickel plating
 * The deposition of a coating of metallic nickel by electrolysis.

nickel pyrite
 * See: millerite.

nickel-skutterudite
 * An isometric mineral, NiAs (sub 2-3) ; isostructural with skutterudite; tin white; in intermediate-temperature hydrothermal veins, particularly in association with Co, Ni, Fe arsenides, sulfarsenides, and native silver. Syn: white nickel.

nickel vitriol
 * See: morenosite.

nicking
 * a. The cutting of a vertical groove in a seam to liberate coal after it has been holed or undercut.

b. Used in wire-rope terminology to describe the internal crosscutting of wires within a rope. c. The chipping of coal along the rib of an entry or room, which is usually the first indication of a squeeze. d. A vertical cutting or shearing one side of a face of coal. Also called cut; cutting.

nickings
 * Newc. The small coal produced in making a nicking. See also: bug dust; makings.

nicol
 * a. Nicol prism.

b. Any apparatus that produces polarized light, e.g., Nicol prism or Polaroid. See also: polar; polarizer.

nicolite
 * A former name for nickeline. See also: nickeline.

Nicol prism
 * A special prism for producing polarized light, made from two pieces of Iceland spar (calcite) cemented together with Canada balsam. Light entering the prism is split into two polarized rays; of these, the ordinary ray is totally reflected at the balsam layer while the extraordinary ray is able to pass through the prism. In a petrological microscope two Nicol prisms are incorporated. See also: polarizing prism.

Niggli's classification
 * a. A classification of igneous rocks on the basis of their chemical composition, similar in some respects to the norm system. It was proposed in 1920 by the Swiss mineralogist Paul Niggli.

b. A classification of ore deposits, the major groups being plutonic, or intrusive, and volcanic, or extrusive. It was proposed in 1929.

night emerald
 * See: evening emerald.

night pair
 * Corn. Miners who work underground during the night. The night shift.

night shift
 * The coal miners' shift from about 12:00 p.m. to 8:00 a.m. It may be a coal-winning shift, but in general it is a preparation or maintenance shift.

nigritite
 * A product of the coalification of fix bitumens rich in carbon; insoluble or only slightly soluble in organic solvents. It is subdivided into polynigritite, humonigritite, exinonigritite, and keronigritite.

nil
 * Nothing; zero. Often used in reporting gold and silver assays.

nine-inch straight
 * A standard 9-in by 4-1/2-in by 2-1/2-in (22.9-cm by 11.4-cm by 6.4-cm) straight brick.

nine-point sample
 * Final sample taken for test when a small quantity of finely ground mineral is required for assay. A suitable quantity of dry material is thoroughly mixed on glazed cloth or paper, if necessary, being rolled lightly with a round bottle to break down any floccules. It is then flattened to a disk and eight equal segments are marked out diametrically with a spatula. Approx. equal quantities are taken from each segment and from the center, making the nine points of withdrawal.

ningyoite
 * An orthorhombic mineral, (U,Ca,Ce) (sub 2) (PO (sub 4) ) (sub 2) .1-2H (sub 2) O ; rhabdophane group; occurs in an unoxidized zone of the Ningyo-toge Mine, Tottori prefecture, Japan.

niobite
 * See: columbite.

niobium
 * A shiny, white, soft, and ductile metallic element. Symbol, Nb (niobium) or Cb (columbium). The name niobium was adopted by the International Union of Pure and Applied Chemistry. Many chemical societies and government organizations refer to it as niobium, but most metallurgists, metals societies, and commercial producers still refer to the metal as columbium. Found in niobite (or columbite), niobite-tantalite, pyrochlore, and euxenite. Used as an alloying agent in carbon and alloy steels, in nonferrous metals, and in superconductive magnets. Syn: columbium.

niobium boride
 * One of several compounds that have been reported, including the following: NbB (sub 2) ; melting point, 3,050 degrees C; sp gr, 7.0; thermal expansion, 5.9 X 10 (super -6) parallel to a and 8.4 X 10 (super -6) parallel to c; NbB, melting point, 2,300 degrees C; sp gr, 7.6; Nb (sub 3) B (sub 4) melts incongruently at 2,700 degrees C; sp gr, 7.3.

niobium nitride
 * One of three nitrides that have been reported: NbN, Nb (sub 2) N, and Nb (sub 4) N (sub 3) . During reaction between niobium and N (sub 2) at 800 to 1,500 degrees C the product generally consists of more than one compound. Most of the phases are stable at least to 1,500 degrees C.

nip
 * a. Where the roof and the floor of a coal seam come close together pinching the coal between them. CF: want.

b. The contact ends of a cable for quick attachment to a power cable. c. The device at the end of the trailing cable of a mining machine used for connecting the trailing cable to the trolley wire and ground. d. To move a machine along a track by sliding the nip along the trolley wire. e. The seizing of material between the jaws or rolls of a crusher. f. See: angle of nip. g. To cut grooves at the end of a bar, to make it fit more evenly. h. An undercutting notch in rock, particularly limestone, along a seacoast between high- and low-tide levels produced by erosion or possible solution.

niperyth
 * See: penthrite.

nipple
 * A tubular pipe fitting usually threaded on both ends and under 12 in (30.5 cm) in length. Longer pipe is regarded as cut pipe. See also: close nipple.

Ni-resist
 * A cast iron consisting of graphite in a matrix of austenite. It contains 3.0% carbon, 14.0% nickel, 6.0% copper, 2.0% chromium, and 1.5% silicon; it has a high resistance to growth, oxidation, and corrosion.

nital
 * See: Boylston's reagent.

niter
 * An orthorhombic mineral, 4[KNO (sub 3) ] ; water soluble; has a cooling salty taste; a product of nitrification in most arable soils in hot, dry regions, and in the loose earth forming the floors of some natural caves. CF: nitratine. Syn: saltpeter. Also spelled nitre.

niter cake
 * Crude sodium sulfate, a byproduct in the manufacture of nitric acid from sodium nitrate.

nitrate
 * a. A salt of nitric acid; e.g., silver nitrate or barium nitrate.

b. A mineral compound characterized by a fundamental anionic structure of NO (sub 3) (super -). Soda niter, NaNO (sub 3), and niter, KNO (sub 3) , are nitrates. CF: carbonate; borate. c. Salts formed by the action of nitric acid on metallic oxides, hydroxides, and carbonates. Readily soluble in water and decompose when heated. The nitrates of polyhydric alcohols and the alkyl radicals explode violently.

nitratine
 * A trigonal mineral, NaNO (sub 3) ; rhombohedral cleavage; water soluble with a cooling taste; occurs only in very arid regions. Formerly called soda niter.

nitrification
 * The formation of nitrates by the oxidation of ammonium salts to nitrites (usually by bacteria) followed by oxidation of nitrites to nitrates. It is one of the processes of soil formation.

nitro
 * An abbrev. for nitroglycerin or dynamite.

nitrocalcite
 * A monoclinic mineral, Ca(NO (sub 3) ) (sub 2) .4H (sub 2) O ; water soluble; soft; occurs as an efflorescence, e.g., on walls and in limestone caves. Syn: wall saltpeter.

nitrocellulose
 * Nitric acid esters of cellulose formed by the action of a mixture of nitric and sulfuric acids on cellulose. The cellulose can be nitrated to a varying extent, ranging from two to six nitrate groups in the molecule. Nitrocellulose having a low nitrogen content, up to the tetranitrate, is not explosive. They dissolve in ether-alcohol mixtures and in so-called lacquer solvents, such as butyl acetate. A nitrocellulose having a high nitrogen content is guncotton, an explosive. The principal nitrocellulose plastic is celluloid. Syn: cellulose nitrate.

nitrocotton
 * A chemical combination of ordinary cotton fiber with nitric acid. It is explosive, highly inflammable, and in certain degrees of nitration, soluble in nitroglycerin.

nitrogelatin
 * See: gelatin dynamite.

nitrogen
 * Colorless, tasteless, odorless, relatively inert element. Symbol, N. Nitrogen makes up 78% of the air, by volume. From this inexhaustible source it can be obtained by liquefaction and fractional distillation. Used in the production of ammonia and nitric acid, as a blanketing medium in the electronics industry, as a refrigerant, in annealing stainless steel, in drugs, and for forcing crude oil from oil wells.

nitrogen fixation
 * a. Extracting nitrogen from the air in commercial quantities for use in agriculture or industry.

b. In a soil, the conversion of atmospheric nitrogen to a combined form by the metabolic processes of some algae, bacteria, and actinomycetes.

nitroglycerin
 * CH (sub 2) NO (sub 3) CHNO (sub 3) CH (sub 2) NO (sub 3) ; pale yellow; flammable; explosive; thick liquid; soluble in alcohol; soluble in ether in all proportions; slightly soluble in water; melting point, 13.1 degrees C; and explosion point, 256 degrees C. Used as an explosive, in the production of dynamite and other explosives, as an explosive plasticizer in solid rocket propellants, and as a possible liquid rocket propellant. Molecular weight, 227.09; triclinic or orthorhombic when solid; sp gr, 1.5918 (at 25 degrees C, referred to water at 4 degrees C); soluble in methanol and in carbon disulfide; very soluble in chloroform; and slightly soluble in petroleum ether. This highly explosive liquid is made by mixing sulfuric acid and nitric acid in a steel tank and then adding glycerin. Its great shattering effect has made it esp. suitable for shooting oil wells. Because of its sensitiveness to shock, liquid nitroglygerin is dangerous to transport and unsuitable for use in mining and quarrying operations. Syn: glycerol trinitrate; trinitrate glycerol; trinitrin; explosive oil.

nitroglycerin explosive
 * An explosive containing, principally, nitroglycerin, nitrocotton, and inorganic nitrates, with a suitable combustible absorbent giving a balanced composition.

nitroglycerin powder
 * Explosive usually characterized by a low nitroglycerin content, up to 10%, and a high ammonium nitrate content of 80% to 85%, with carbonaceous material forming the remainder of the composition. This composition produces a powdery consistency and, consequently, nitroglycerin powders have relatively poor water-resistance properties, so that they should be used only in dry conditions. Their storage properties are fairly good, but this is largely dependent on the protection given after manufacture, for example, in the methods of cartridging and packing. The main application of these explosives is in quarrying and mining where the ground to be blasted is relatively soft.

nitrohydrochloric acid
 * See: aqua regia.

nitrolite
 * An excellent and cheap explosive in powder form, consisting of the constituents ammonium nitrate + trotyl + nitroglycerin + silicon.

nitromagnesite
 * A monoclinic mineral, Mg(NO (sub 3) ) (sub 2) .6H (sub 2) O ; water soluble; white; an efflorescence in limestone caverns.

nitromuriatic acid
 * See: aqua regia.

nitrostarch explosive
 * Nitrostarch explosives have been used to a limited extent for over 50 years. When these explosives were first introduced, nitrostarch was the principal explosive ingredient in their composition. Of recent years, because of the trend toward the low-sensitivity, noncap sensitive nitrocarbonitrates and ammonium nitrate-oil mixtures, certain grades of explosives are being produced with low amounts of sensitizers. Some of these explosives today contain a very large percentage of ammonium nitrate, and nitrostarch is used only in small quantities to act as a sensitizer.

nitrosubstitution
 * The act or process of introducing by substitution the nitryl radical, NO (sub 2), in place of one or more replaceable hydrogen atoms, such as in an organic compound. Nitrosubstitution compounds are used in the manufacture of some explosives.

nitrosulfuric acid
 * An exceedingly corrosive mixture of one part by weight of nitric acid and two parts by weight of sulfuric acid. Used in the manufacture of nitroglycerin.

nitrous oxide
 * A gas with the chemical formula, N (sub 2) O ; molecular weight, 46; sp gr, 1.6. This gas is produced by the blasting of certain nitroglycerine explosives, esp. if there is incomplete detonation. It is also produced in the exhaust of diesel locomotives. It is used as an anesthetic in dentistry and is commonly known as laughing gas.

niveau surface
 * See: equipotential surface.


text:
афсона

Noun

 * 1) tale
 * 2) story
 * 3) fable
 * 4) legend

title: афсона