Appendix:Dictionary of Mining, Mineral, and Related Terms/C/9

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C.S. jar collar

A thick-wall steel collar, the inside surface of which is tapered to fit two serrated-face taper sleeves. The assembly may be fitted at any point over a casing or pipe and serves as a drive collar in sinking casing or pipe by driving and chopping. Also called self-tightening jar collar; self-tightening jar coupling; Simmons jar block, Simmons jar collar.

C.T. Nozzle

Trade name; a refractory nozzle for steel pouring designed to give a constant teeming rate (therefore, the name). The nozzle consists of an outer fireclay shell and a refractory insert of different composition. Strictly speaking, the term refers to a particular type of insert developed for the teeming of free cutting steels.


An orthorhombic mineral, CuFe (sub 2) S (sub 3) ; dimorphous with isocubanite. Formerly called chalmersite.


A niche cut in the rib or wall of an underground mine for the storage of explosives or detonators.


a. Scot. A ventilating furnace in a mine.

b. A relatively rare crystal form of diamond having six equal-area faces at right angles to each other. c. A rectangular prism having squares for its ends and faces. d. A crystal form of six equivalent (not necessarily square) and mutually perpendicular faces, with indices of 100. e. A hexahedron, a crystal form of the isometric system consisting of six mutually orthogonal planar faces. Conditions of growth may yield crystal faces that are not perfectly square, but are at mutual right angles. f. A diamond in cube form. g. Dice, e.g., pyrite cubes known locally as devil's dice. h. Pseudocubic forms, e.g., quartz rhombohedra with faces at near right angles, tetragonal prisms capped by a basal pinacoid, orthorhombic prisms or domes terminated by a pinacoid, or three orthorhombic pinacoids of nearly equal areas.

cube ore

Eng. An arsenate of iron, KFe (sub 4) (AsO (sub 4) ) (sub 3) (OH) (sub 4) .6-7H (sub 2) O , of an olive-green to yellowish-brown color, and occurring commonly in cubes with the copper ores of Cornwall. Syn: pharmacosiderite.

cube powder

Gunpowder made in large cubical grains and burning more slowly than the small or irregular grains.


a. Having the form of a cube, as a cubic crystal; or referring to directions parallel to the faces of a cube, as cubic cleavage. See also: cubic system.

b. Crystal cleavage with three planes at mutual right angles. c. An alternate name for the isometric crystal system. See also: isometric. d. In crystal structures, a cation coordination of six equidistant anions.

cubic cleavage

a. Equally good cleavage in three mutually perpendicular directions.

b. Mineral cleavage parallel to the faces of a cube, e.g., in galena or halite.

cubic foot per minute

A standard capacity or performance measurement for compressors.


A cubic zeolite; analcime. Also spelled cubizite.

cubic packing

The loosest manner of systematic arrangement of uniform solid spheres in a clastic sediment or crystal lattice, characterized by a unit cell that is a cube whose eight corners are the centers of the spheres involved. An aggregate with cubic packing has the maximum porosity (47.64%).

cubic plane

Any plane normal to one of the crystallographic axes in the isometric system having Miller indices 100 .

cubic system

The crystal system that has the highest degree of symmetry; it embraces such forms as the cube and the octahedron. See also: cubic.


a. A crystal form that has faces of both the cube and the dodecahedron.

b. The combined isometric form of a cube modified by an octahedron or an octahedron modified by a cube.

cuckoo shots

Subsidiary shots in the roof of a longwall working, between the coal face and the waste, or in any waste.

cuddy brae

Scot. An inclined roadway, worked in the same manner as a self-acting incline.


a. A hill or ridge with a gentle slope on one side and a steep slope on the other; specif. an asymmetric ridge (as in the Southwestern United States) with one face (dip slope) long and gentle and conforming with the dip of the resistant bed or beds that form it, and the opposite face (scarp slope) steep or even cliff like and formed by the outcrop of the resistant rocks, the formation of the ridge being controlled by the differential erosion of the gently inclined strata.

b. A ridge or belt of low hills between lowlands in a region of gently dipping sedimentary rocks (as on a coastal plain), having a gentle slope conforming with the dip of the rocks and a relatively steep slope descending abruptly from its crest.---Etymol: Spanish, flank or slope of a hill; hill, mount, sloping ground. CF: hogback; wold; scarp; escarpment.


Sp. A cave or grotto.


The part of a brillant-cut stone below the girdle.


a. The small lower terminus of a brilliant-cut gem. It is parallel to the table.

b. The small facet that is polished parallel to the girdle plane across what would otherwise be the sharp point or ridge that terminates the pavilion of a diamond or other gemstone. Its principal function is to reduce the possibility of damage to the gemstone. Also spelled collet.


a. A vernacular term variously applied, according to the locality, to carbonaceous shale, or to fissile varieties of anthracite coal.

b. English Anthracite; a kind of coal, of indifferent quality, burning with a small flame, and emitting a disagreeable odor. c. Anthracite fines that will pass through a screen with 1/8-in holes. d. In anthracite terminology, the waste accumulation of coal, bone, and rock from old dry breakers. e. In bituminous coal preparation, culm corresponds to slurry or slime, depending upon the size distribution of the suspended solids. f. Kolm. g. The anthracite contained in the series of shales and sandstones of North Devon, England, known as the Culm Measures. h. Coal dust or fine-grained waste from anthracite mines. Syn: kulm.

culm bank

The deposit on the surface of culm usually kept separate from deposits of larger pieces of slate and rock. Also called culm dump.


Containing culm as coal.


The highest point of a structural feature, e.g., of a dome or anticlinal crest. The axis of an anticline may have several culminations that are separated by saddles. See also: crest. Syn: apex.

culture tube

See: acid-etch tube.


a. Same as volgerite.

b. A tetragonal mineral, Pb (sub 21) Cu (sub 20) Cl (sub 42) (OH) (sub 40). Also spelled cumengeite.


A monoclinic mineral, (Fe,Mg) (sub 7) Si (sub 8) O (sub 22) (OH) (sub 2) ; amphibole group; has Mg/(Mg + Fe (super 2+) ) = 0.30 to 0.69 ; prismatic cleavage; may be asbestiform; in amphibolites and dacites; fibrous varieties (amosite, magnesium rich, and montasite, iron rich) are used as asbestos.


An igneous rock formed by the accumulation of crystals that settle out from a magma by the action of gravity; examples include layered igneous deposits such as the Bushveld complex in South Africa and the Stillwater complex in Montana. Syn: accumulative rock.

cumulative float curve

The curve obtained from the result of a float and sink analysis by plotting the cumulative yield at each specific gravity against the mean ash of the total floats at that specific gravity.

cumulative plot

Graphic representation of cumulative curve results of screen analysis, in which the cumulative percentage of weight is plotted against the screen aperture, usually both to logarithmic scale.

cumulative sink curve

The curve obtained from the results of a float and sink analysis by plotting the cumulative yield of sinks at each specific gravity against the mean ash of the total sinks at that specific gravity.


Said of the texture of a porphyritic igneous rock in which the phenocrysts, not necessarily of the same mineral, are clustered in irregular groups; also said of a rock exhibiting such texture. Syn: glomeroporphyritic.


a. Scot. The spaces from which coal has been worked out, partly filled with dirt and rubbish between the packs. See also: openset; goaf.

b. Aust. The passage under a roadway into which an endless rope passes out of the way at the end of its track. Also called conduct. A variation of conduit. c. Any small passageway made to improve ventilation or facilitate movement of materials. It is generally made through a pack or along the rib side of a longwall face. See also: airhole.

cup and cone

A machine for charging a shaft furnace, consisting of an iron hopper with a large central opening, which is closed by a cone or bell pulled up into it from below. In the annular space around this cone, the ore, fuel, etc., are placed, then the cone is lowered to drop the materials into the furnace, after which it is again raised to close the hole. Syn: bell and hopper; closed top.


a. A small bone-ash cup used in gold or silver assaying with lead.

b. The hearth of a small furnace used in refining metals.


a. The process of assaying for precious metals with a cupel.

b. Oxidation of molten lead containing gold and silver to produce lead oxide, thereby separating the precious metals from the base metal.


One who refines gold and silver in a type of reverberatory furnace known as a cupel.


A colorless crystalline salt, C (sub 6) H (sub 5) N(NO)ONH (sub 4) , that is a precipitant for copper and iron from solutions and is also used in the analysis of other metals, esp. of the uranium group. Used for separating iron and copper from other metals. Precipitates iron quantitatively from strongly acid solutions.


a. A cylindrical vertical furnace for melting metal, esp. gray iron, by having the charge come in contact with the hot fuel, usually metallurgical coke.

b. A dome-shaped projection of the igneous rock of a batholith. Many stocks are cupolas on batholiths. CF: roof pendant.

cupola furnace

A shaft furnace used in melting pig iron (with or without iron or steel scrap) for iron castings. Metal, coke, and flux (if used) are charged at the top, and air is blown in near the bottom.

cupreous manganese

See: lampadite.

cupric sulfide

See: copper sulfide.


Yielding or containing copper.

cupriferous pyrite

See: chalcopyrite.


An isometric mineral, Cu (sub 2) O ; red (crimson, scarlet, vermillion, brownish-red); sp gr, 6.1; in oxidized parts of copper veins; an important source of copper. Also called ruby copper; ruby copper ore. Syn: red copper ore; red copper oxide; red glassy copper ore; red oxide of copper; octahedral copper; cuprous oxide; copper suboxide. See also: chalcotrichite; plush copper ore.


A variety of apatite from Chile containing copper.


A former name for auricupride. Syn: gold cupride.


A mixture of cuprite and calcite(?).


A triclinic mineral, CuFe (sub 4) (SO (sub 4) ) (sub 6) (OH) (sub 2) .20H (sub 2) O ; copiapite group.


A former name for mottramite.


A variety of melanterite containing copper (4.40% CuO) and magnesium (4.29% MgO). Also spelled kuprojarosit. See also: jarosite.


A magnesian cuprian variety of melanterite.


A monoclinic copper magnesium sulfate in bluish-green crusts at Mt. Vesuvius, Italy; of doubtful validity.


Interpretation of the Russian name medmontite. See also: medmontite.


A former name for bayldonite.


A tetragonal mineral, CaCuSi (sub 4) O (sub 10) ; in small blue grains at Mt. Vesuvius, Italy.


A triclinic mineral, (H (sub 3) O) (sub 2) Cu(UO (sub 2) ) (sub 2) (SiO (sub 4) ) (sub 2) .2H (sub 2) O ; strongly radioactive; greenish-yellow or grass-green; a secondary mineral resulting from alteration of pitchblende associated with other uranium minerals.

cuprous oxide

See: cuprite.


a. A timber frame, circular or square, wedged in a shaft to make a foundation for walling or tubbing, or to support, with or without other timbering, the walls of the shaft.

b. The heavy frame or sill at the top of a shaft. c. In tunnel construction, a ring of brickwork or of cast iron, at the base of the shaft, surmounting a circular orifice in the roof of the tunnel. A drum curb is a flat ring of cast iron for supporting the brickwork having the same diameter externally as the shaft of brickwork. Temporary curbs of oak are also used. d. An iron border to the incorporating bed of a gunpowder mill. e. An iron casing in which to ram-load molds for casting. f. The walls of a chamber in which sulfuric acid is manufactured. g. A wood, cast-iron, or reinforced concrete ring, made in segments, forming a foundation for a masonry or cast-iron circular shaft lining. The curb is set on a firm ledge of rock notched into the periphery of the shaft. It may be removed at a later stage. Syn: wedging curb; bricking curb; crib; walling curb. See also: foundation curb; water ring. h. A socket of wrought iron or steel for attaching a ring hook or swivel to the end of a rope used for mine hoisting or haulage. i. A coaming around the mouth of a well or shaft. See also: binder. j. A shaft support ring for walling or tubbing.

curb tubbing

Eng. A solid wood lining of a shaft. Syn: curb.


A unit of measurement of radioactivity, defined as the amount of a radionuclide in which the decay rate is 37 billion disintegrations per second, which is approx. equal to the decay rate of 1 g of pure radium.

Curie point

The temperature at which there is a transition in a substance from one phase to another of markedly different magnetic properties. Specif., the temperature at which there is a transition between the ferromagnetic and paramagnetic phases.

Curie's law

The susceptibility of a paramagnetic substance is inversely proportional to the absolute temperature. A law of magnetism that has been replaced by the Curie-Weiss law.

Curie temperature

The temperature of magnetic transformation below which a metal or alloy is magnetic and above which it is paramagnetic.


An orthorhombic mineral, Pb (sub 2) U (sub 5) O (sub 17) .4H (sub 2) O ; radioactive; orange-red; an alteration product of uraninite.


Shrop. Ironstone exhibiting cone-in-cone formation.

curly coal

A folded and distorted oil shale.

curly stone

Shrop. Shale belonging to the coal formation, which on exposure to the air hardens and assumes a peculiar form, sometimes called cone-upon-cone. Also called curlstone.


a. The part of a fluid body esp. as air or water, that is moving continuously in a definite direction, often with a velocity much swifter than the average, or in which the progress of the fluid is principally concentrated.

b. A horizontal movement or continuous flow of water in a given direction with a more or less uniform velocity, producing a perceptible mass transport, set in motion by winds, waves, gravity, or differences in temperature and density, and of a permanent or seasonal nature, esp. an ocean current. c. The velocity of flow of a fluid in a stream. d. The swiftest part of a stream. e. A tidal or a nontidal movement, often horizontal, of lake or ocean water. Syn: drift. f. Condition of flowing. Flow marked by force or strength. Syn: flow; flux.

current bedding

Any bedding or bedding structure produced by current action; specif. cross-bedding resulting from water or air currents of variable direction. See also: false bedding. Syn: inclined bedding.

current density

The current per unit area perpendicular to the direction of current flow.

current electrode

a. A piece of metal connected to a cable that, when buried in the earth in a shallow hole or lowered into a well, provides enough contact to permit the passage of substantial electrical current into the surrounding earth.

b. A metal contact with the ground used to facilitate current flow through the ground.

current leakage

Portion of the firing current bypassing part of the blasting circuit through unintended paths.

current leakage tester

See: earth fault tester.

current-limiting device

An electric or electromechanical device that limits current amplitude; duration of current flow; or total energy of the current delivered to an electric blasting circuit.

current meter

a. Any one of numerous instruments for measuring the speed alone, or both speed and direction, of flowing water, as in a stream or the ocean; it is usually activated by a wheel equipped with a set of revolving vanes or cups whose rate of turning is proportional to the velocity of the current.

b. An instrument, as a galvanometer, for measuring the strength of an electric current.

current rose

A graphical representation of currents, usually by 1 degrees quadrangles, using arrows of different lengths for the cardinal and intercardinal compass points to show resultant drift and frequency of set for a given period of time.

curry pit

Leic. A hole sunk from an upper to a lower portion of a thick seam of coal through which the return air passes from the stalls to the airway.

cursing in work

Can. False affidavit of assessment work on mining claims.


a. A sheet of brattice cloth hung across an entry in such a way as to prevent the passage of an air current but not to hinder the passage of mules or mine cars. In coal mines, curtains are used to deflect the air from the entries into the working rooms and to hold the air along the faces. They are usually made of a number of overlapping strips of heavy curtain material, that should be of fireproof or fire-resistant material. Syn: check curtain. See also: blasting curtain.

b. Also called cover. c. A thin sheet of dripstone hanging from the ceiling or projecting from the wall of a cave. d. A rock formation that connects two neighboring bastions. e. One of a series of steps cut in a valley side and exaggerated by cultivation.

curtain hole

See: cover hole.


a. A crystalline hydrocarbon, found in a form of greenish deposits from a hot spring in California.

b. A former name for idrialite.

curvature of gravity

A vector quantity calculated from torsion-balance data indicating the shape of the equipotential surface. It points in the direction of the longer radius of curvature.

curved jib

A chain coal cutter jib with the outer end bent upward or downward through 90 degrees . Thus, the machine can make a horizontal and also a vertical cut in one operation. Curved jibs make coal preparation easier, but their use is limited because of the excessive strain and wear on the cutter chain. See also: turret jib; multicut chain.


A unit of waterflow or airflow that equals 1 ft (super 3) /s (0.028 m (super 3) /s).

cushat marl

See: cowshut.


A course of some compressible substance, such as soft wood, inserted between more rigid material. In mine support, it can be placed between the footwall or the hanging wall and the concrete, or internally in the support.

cushion blasting

A method of blasting in which an airspace is left between the explosive charge and the stemming, or in which the shothole is of substantially larger diameter than the cartridge. See also: controlled blasting.

cushion cut

A style of faceting gems in which the finished gem is roughly rectangular in outline but with gently outward curving sides and rounded corners.

cushion firing

See: water-ampul stemming.

custom mill

A mill that depends on purchased ores mostly or entirely for processing rather than on its own organizational source.

custom ore

Ore bought by a mill or smelter, or treated for customers.

custom plant

A mill, concentrator, or smelter that purchases ore or partly processed mineral for treatment in terms of an appropriate contract, priced on tonnage, complexity of operation, permissible losses, and specification of feed, product, and (perhaps) lost tailings.

custom smelter

a. A smelter which buys ores or treats them for customers.

b. A smelter which depends for its intake mostly on concentrate purchased from independent mines and on scrap metal, rather than its own captive mine sources.


a. An arrangement of holes used in underground mining and tunnel blasting to provide a free face to which the remainder of the round can break. Also, the opening created by the cut hole.

b. To intersect a vein or working. c. To shear one side of an entry or crosscut by digging out the coal from floor to roof with a pick. See also: undercut. d. Eng. In Somerset, a staple or drop pit. e. Eng. The depth to which a drill hole is put in for blasting. f. A term applied where the cutting machine has cut under the coal. g. The drill-hole pattern for firing a round of shots in a tunnel or sinking shaft, e.g., the burn cut. h. A machine cut in a coal seam; e.g., floor cut. i. See: stint; sump. j. An excavation, generally applied to surface mining; to make an incision in a block of coal; in underground mining, that part of the face of coal that has been undercut. k. In mining, when used in conjunction with shaft and drift, a surface opening in the ground intersecting a vein. l. Depth to which material is to be excavated (cut) to bring the surface to a predetermined grade; the difference in elevation of a surface point and a point on the proposed subgrade vertically below it. m. To excavate coal. n. To drive to or across a lode. o. The groups of holes fired first in a round to provide additional free faces for the succeeding shots. p. To lower an existing grade.

cut-and-fill stoping

A stoping method in which the ore is excavated by successive flat or inclined slices, working upward from the level, as in shrinkage stoping. However, after each slice is blasted down, all broken ore is removed, and the stope is filled with waste up to within a few feet of the back before the next slice is taken out, just enough room being left between the top of the waste pile and the back of the stope to provide working space. The term cut-and-fill stoping implies a definite and characteristic sequence of operations: (1) breaking a slice of ore from the back; (2) removing the broken ore; and (3) introducing filling. See also: underhand longwall.

cut-chain brae

cut holes

a. The first hole or group of holes fired in a drift or tunnel face. Also known as the cut portion of the blasting round.

b. In tunneling, easers so drilled and fired as to break out a leading wedge-shaped hole and thus enable the later holes in the complete round of shots to act more effectively. See also: trimmers; drill-hole pattern.


a. A variety of exinite. The micropetrologic constituent, or maceral, of cuticular material. CF: sporinite.

b. Maceral of the exinite group consisting of plant cuticle. CF: resinite.

cutinite coal

This type of coal consists of more than 50% of cuticle, the fragments of which occur embedded in gelito-collinite, fusinito-collinite, and collinite of fusinitic nature. In addition to cuticle, spores, resin bodies, and fragments of finely fusinized and gelified tissue are present. Leaf parenchyme and stem tissue, bordered by cuticle, may also be seen. Hand specimens of this type of coal are grayish-black, matt or semimatt, finely striated, or sometimes even banded. The coal breaks angularly and generally has high ash. Cutinite coal occurs as thin bands in seams of different geological age, and its use is largely determined by the other forms of coal with which it is associated.


a. In firing a round of shots, a misfire due to severance of fuse owing to rock shear as adjacent charge explodes.

b. A quarryer's term for the direction along which granite must be channeled, because it will not split. Same as hardway. c. CF: cutoff entry. d. The number of feet a bit may be used in a particular type of rock (as specified by the drill foreman). e. An impermeable wall, collar, or other structure placed beneath the base or within the abutments of a dam to prevent or reduce losses by seepage along a construction interface or through porous or fractured strata. It may be made of concrete, compacted clay, interlocking sheet piling, or grout injected along a line of holes. f. A boundary, oriented normal to bedding planes, that marks the areal limit of a specific stratigraphic unit where the unit is not defined by erosion, pinchout, faulting, or other obvious means. Cutoffs are applicable to map, cross-sectional, and three-dimensional views, and are in effect specialized facies boundaries. g. Minimum percentage of mineral or metal in an ore that can be mined profitably. h. A device for cutting off; as a mechanism for shutting off the admission of a working fluid (as steam) to an engine cylinder. i. The point in the stroke of the piston of a steam engine at which the entrance of live steam is stopped by the closure of the inlet valve.

cutoff entry

An entry driven to intersect another and furnish a more convenient outlet for the coal. CF: cutoff. See also: entry.

cutoff grade

The lowest grade of mineralized material that qualifies as ore in a given deposit; rock of the lowest assay included in an ore estimate.

cutoff hole

Missed hole resulting from the failure of a blasting cap to detonate owing to the breaking of a fuse or conductor or to some other similar cause.

cutoff shot

A shot in a delay round in which the charge has been wholly or partially exposed to the atmosphere by reason of the detonation of an earlier shot in the round.


a. Opening made in a mine working in which a drill or other equipment may be placed so as not to interfere with other mining operations.

b. The act or process of removing diamonds from a used or dull bit by dissolving the crown metal by corrosive action of an acid or electrolytic dissolution. Also, the diamonds recovered or salvaged by such means. c. A mass of shale, siltstone, or sandstone filling an erosional channel cut into a coal seam. CF: low; roll; washout. Syn: horseback; want.

cut point

The value of a property (e.g., density or size) at which a separation into two fractions is desired or achieved.

cut shot

a. A shot designed to bring down coal that has been sheared or opened on one side.

b. A shot that initially breaks ground to provide a free face for subsequent shots.

cut stone

a. Originally, an artificially broken and shaped carbon; now generally, a faceted diamond or other precious or semiprecious gemstone used as an ornament. Syn: gem.

b. Structural unit for limestone that consists of blocks that are cut to specified dimensions and surface tooled.


Diamond material suitable for cutting into gems.


a. A joint in a rock that is parallel to the dip of the strata.

b. A crack in a crystal that destroys or lessens its value as a lapidary's stone. c. On a hydraulic dredge, a set of revolving blades at the end of the suction line. d. Closed or inconspicuous seams along which rock may separate or break easily. e. Any coal-cutting or rock-cutting machine; or the person operating it. f. A solution crevice in limestone underlying Tennessee residual phosphate deposits. g. See: underreamer lug. CF: cutting edge.

cutter bar

That part of a chain mining machine that supports the cutting chain and extends under the coal; the bar provides the track for the cutting chain.

cutter chain

The endless chain carrying picks that travels around the jib of a chain coal cutter at a speed varying from 320 to 650 ft/min (97.6 to 198.2 m/min). See also: coal-cutter pick.

cutter dredge

In alluvial mining, one that loosens the alluvium by means of a cutting ring, at the end of a suction pipe through which the products are pumped up for treatment.

cutterhead pipeline dredge

A hydraulic dredge in which the suction action is augmented by a rotating propeller that operates at the point of suction. The cutterhead performs two functions: it cuts into and loosens compacted soils and soft rock such as coral, and it increases dredge capacity by channeling the soils into the end of the suction pipe. The efficiency of a dredge is based on its capacity to handle soils rather than water, and the cutterhead serves to maintain an optimum ratio of about 1 ft (super 3) (0.028 m (super 3) ) of soil handled per 5 ft (super 3) (0.14 m (super 3) ) of water.

cutter loader

A longwall machine that cuts and loads the coal onto a conveyor as it travels across the face. See also: loader.

cutter plow

A plow-type cutter loader developed for use in hard coal seams. It has four horizontal stepped precutting blades, which make a precut from 8 to 12 in (20.3 to 30.5 cm), to weaken the coal immediately in front of the machine. It can be single or double ended, and is hauled along the face by winches. The coal is loaded onto a panzer conveyor, which is advanced behind the machine by compressed air rams. See also: plow.


A passage cut through the coal, connecting two parallel entries. See also: crosscut; breakthrough; jack hole.


a. The opening made by shearing or cutting.

b. Low-grade ore or refuse obtained from beneficiating ore. c. The operation of making openings across a coal seam as by channeling, or beneath a coal seam as by undercutting. d. Excavating. e. Lowering a grade. f. Eng. The end or side of a stall next to the solid coal where the coal is cut with a pick in a vertical line to facilitate breaking down; channeling. g. N. of Eng. The operation of undercutting coal with a mechanical cutter. The machine, which runs on electricity, employs two cutterpersons.

cutting chain

The sprocket chain that carries the steel points used for undermining the coal with chain mining machines.

cutting down

a. The trimming of shaft walls to increase their sectional area.

b. Removing roughness or irregularities of a metal surface by abrasive action.

cutting edge

a. The point or edge of a diamond or other material set in a bit that comes in contact with and cuts, chips, or abrades the rock. Also called cutting point. CF: cutting stones.

b. That part of a bit in actual contact with rock during drilling operations. c. The leading edge of a lathe tool where a line of contact is made with the work during machining. CF: cutter.

cutting face

That part of a bit containing the cutting points, excluding the points inset as reamers.

cutting fluid

A fluid, usually a liquid, used in metal cutting to improve finish, tool life, or dimensional accuracy. On being flowed over a tool and a workpiece, the fluid reduces friction, heat generated, and tool wear, and prevents galling. It conducts heat away from the point of generation and also serves to wash chips away.

cutting grain

The direction along a plane on which a diamond can be most easily abraded.

cutting horizon

The position in a coal seam in which a horizontal machine cut is made. The normal cutting horizon is along the bottom of the seam. See also: bottom cut.

cutting machine

A power-driven machine used to undercut or shear the coal to facilitate its removal from the face.

cutting motor

The motor in a cutting machine that provides power for the operation of the cutting chain.


a. The particles of rock produced in a borehole by the abrasive or percussive action of a drill bit; excess material caused by the rubbing of core against core or core against steel; erosive effect of the circulating liquid; or cavings from the borehole. Also called drill cuttings; drillings; sludge. CF: borings.

b. The fragmental rock samples broken or torn from the rock penetrated during the course of drilling. c. Eng. See: holings. d. See: bug dust.

cutting sand

Composed of sharp, solid quartz grains and used as abrasive for sawing stone; usually ungraded and about equivalent to a No. 1 sandblasting sand.

cutting speed

a. The linear or peripheral speed of relative motion between a tool and a workpiece in the principal direction of cutting.

b. See: feed rate.

cutting stones

Diamonds set in a bit face having points or edges that will be in contact with, and will cut or abrade, the rock when drilling. CF: cutting edge; gage stone.

cutting wheel

A cutting disk, the edge of which is impregnated with an abrasive, such as diamond dust or aloxite. It is rotated at high speed in a coolant and used to cut rock specimens into suitable thin sections for microscopic inspection in transmitted light with a polarized-light microscope or, after polishing, with a reflected-light (ore) microscope.

cutty clay

Plastic clay formerly used in England for making tobacco pipes; "pipe clay."


A large-scale basin in which sedimentation has occurred or is taking place, as distinguished from a tectonic basin due to folding of preexisting rocks; e.g., the Anglo-Parisian cuvette of Southeast England and Northeast France, in which Cenozoic rocks accumulated and were later folded into several distinct but smaller basins, such as the London Basin and the Paris Basin. Etymol: French, small tub or vat. Sometimes misspelled curvette.

Cuylen conveyor

A single-chain conveyor with an open side to facilitate power loading.


The name of an iron range in Minnesota. It is composed of the syllables, "Cuy" and "Una," the former being a contraction of the given name of Cuyler Adams, who was active in the early development of that territory, and the last syllable being the name of his dog "Una."


See: coupled wave.


White; crystalline; NH (sub 2) CN . Formed variously by the action of cyanogen chloride on ammonia.


Any substance present in a pulp that attacks or destroys the cyanide salt being used to dissolve precious metals.


A process of extracting gold and silver as cyanide slimes from their ores by treatment with dilute solutions of potassium cyanide or sodium cyanide. The slimes are subsequently fused and cast into ingots or bullion.

cyanidation vat

A large tank, with a filter bottom, in which sands are treated with sodium cyanide solution to dissolve out gold.


Usually refers to cyanide solution in circulation in a mill treating gold or silver ores. The stock or solution is of two main types: barren, from which all possible value has been extracted, and pregs or pregnant, which is charged with gold or silver and awaits their removal.

cyanide hardening

Introducing carbon and nitrogen into the surface of a steel alloy by heating in a bath of molten sodium cyanide and usually followed by quench hardening.

cyanide man

In ore dressing, smelting, and refining, a person who tends equipment in which finely ground gold or silver ore is treated with a cyanide solution to separate free gold or silver from the gangue (waste material).

cyanide mill

See: cyanide process.

cyanide process

A process for the extraction of gold from finely crushed ores, concentrates, and tailings by means of cyanide of potassium or sodium used in dilute solutions. The gold is dissolved by the solution and subsequently deposited upon metallic zinc or other materials. Syn: cyanide mill. See also: MacArthur and Forest cyanide process.

cyanide pulp

The mixture obtained by grinding crude gold and silver ore and dissolving the precious-metal content in a sodium-cyanide solution.

cyanide slime

Precious metal in the form of finely divided particles precipitated from a cyanide solution used in its extraction from ore.


The process of treating finely ground gold and silver ores with a weak solution of sodium or potassium cyanide, which readily dissolves these metals. The precious metals are then obtained by precipitation from solution with zinc, or by adsorbtion on activated carbon.


A former spelling of kyanite.


A phosphoriferous variety of chrysocolla from Nijni Tagilks, Perm, Russia.


A monoclinic mineral, K (sub 2) Cu(SO (sub 4) ) (sub 2) .6H (sub 2) O ; picomerite group; a clear-blue alteration product from Mt. Vesuvius, Italy.


a. A univalent radical; present in hydrogen cyanide and in other simple and complex cyanides (as ferricyanides).

b. Colorless, flammable, poisonous gas; (CN) (sub 2) . It has an odor like that of peach leaves, is variously formed (as by heating mercuric cyanide), and polymerizes readily.


A former name for chalcanthite. Also spelled cyanose.


An orthorhombic mineral, Cu (sub 4) Al (sub 2) (SO (sub 4) )(OH) (sub 12) .2H (sub 2) O ; sky-blue to smalt-blue; minutely crystalline or spheroidal. Formerly called lettsomite. Syn: velvet copper ore.

cycle of denudation

Cycle of erosion.

cycle of erosion

The complete series of changes or stages through which a landmass passes from the inception of erosion on a newly uplifted or exposed surface through its dissection into mountains and valleys to the final stage when it is worn down to the level of the sea or to some other base level. The cycle is usually subdivided into youthful, mature, and old-age stages. One type or many types of erosion may be involved, and the landforms produced and destroyed depend to a large extent on the climate, geographic situation, and geologic structure of the landmass. Syn: cycle of denudation; geographic cycle; geomorphic cycle.

cycle of operations

In mining operations, such as tunnel driving, shaft sinking, and coal winning, there are certain tasks that must be repeated in cyclic fashion. In tunnel driving, they are (1) drilling the round; (2) charging and firing; (3) loading; and (4) supporting and track extension. This cycle of operations is time analyzed to achieve maximum efficiency and speed.

cycle of sedimentation

a. A sequence of related processes and conditions, repeated in the same order, that is recorded in a sedimentary deposit.

b. The deposition of sediments in a basin between the beginnings of two successive marine transgressions, comprising the deposits formed initially on dry land, followed by shallow-water and then deep-water deposits that in turn gradually change to shallow-water and then dry-land type during a marine regression. c. See: cyclothem; sedimentary cycle.

cycle skipping

An instrumental phenomenon occurring in acoustic velocity logs. It consists of intervals where the velocity recorded drops sharply to very low values, and equally sharply, returns to a normal scale figure. Such a log is spiky.

cycle time

The time required for the dipper of a mechanical shovel to push through the bank and fill, swing to the haul unit, unload, and swing back to the digging position. Cycle time is established under standard conditions of a 90 degrees angle of swing and with an optimum depth of cut.


Adj. of cycle; recurrent rather than secular.

cyclic mining

A mining system in which each shift has a specific task to complete on the conveyor face. If the task on any shift is not completed in time, the following shifts are disorganized. In general, the face is machine cut during the night shift; shot-firing and hand-filling of the coal occupy the day shift; and the afternoon shift is responsible for moving the conveyor and roof supports to the new line of face. See also: conventional machine mining; conventional mining.

cyclic surge

In classification, periodic upset of correct separating density of pulp, resulting in wrong release of oversize material from the closed grinding circuit.

cyclic test

In batch tests of small quantities of ore during development of a method of concentration, the retention of selected fractions (usually middlings) for admixture with fresh samples. Used to study effect of recycling minerals or solutions, which they may have contaminated; also, to observe effects of increased concentration of such compounds on the process as a whole. See also: locked test.

cyclic twin

Repeated twinning of three or more individual crystals according to the same twin law but with the twin axes or twin planes not parallel, commonly resulting in threefold, fourfold, fivefold, sixfold, or eightfold twins, which, if equally developed, display geometrical symmetry not found in single crystals, e.g., chrysoberyl, rutile. CF: repeated twinning; polysynthetic twinning.

cyclic twinning

The repeated twinning of three or more individuals according to the same twin law but with the twinning axes not parallel. Often simulates a higher order of symmetry than that of the untwinned crystal. CF: polysynthetic twinning.

cyclic winding

See: automatic cyclic winding.


a. The conical-shaped apparatus used in dust collecting operations and fine grinding applications. In principle, the cyclone varies the speed of air, which determines whether a given particle will drop through force of specific gravity or be carried through friction of the air.

b. A classifying (or concentrating) separator into which pulp is fed, so as to take a circular path. Coarser and heavier fractions of solids report at apex of long cone while finer particles overflow from central vortex. Also called hydrocyclone. See also: cyclone washer; centrifugal separation; centrifuge.

cyclone angle

Included angle of conical section of hydrocyclone.

cyclone classifier

A device for classification by centrifugal means of fine particles suspended in water, whereby the coarser grains collect at and are discharged from the apex of the vessel, while the finer particles are eliminated with the bulk of the water at the discharge orifice.

cyclone dust collector

An apparatus for the separation by centrifugal means of fine particles suspended in air or gas.

cyclone furnace

A forced circulation heat treatment furnace designed to operate at a maximum temperature of 760 degrees C, which is either gas fired or electrically heated. The gas circulates at the rate of 0.89 m/s.

cyclone overflow

A finer classified fraction, which leaves via the vortex finder of a hydrocyclone.

cyclone separator

A funnel-shaped device for removing material from an airstream by centrifugal force.

cyclone size

Diameter of cylindrical section of hydrocyclone. Also diameter of inlet orifice if round. Dimensions or area in given inches or square inches if opening is rectangular.

cyclone underflow

A coarser sized fraction, which leaves via apex aperture of hydrocyclone.

cyclone washer

Cyclone washing of small coal originates from the Netherlands. Clean separation is effected with the aid of centrifugal force. The heavier shale particles move to the wall of the cyclone and are eventually discharged at the bottom while the lighter coal particles are swept toward the central vortex and are discharged through an outlet at the top. The washer may be used for cleaning coal up to 3/4 in (1.9 cm). The coal is normally deslimed at about 0.5 mm before cleaning. The separating medium is water and ground magnetite, the bulk of which is recovered and returned to the circuit. A 20-in (50.8-cm) cyclone has a feed capacity of about 50 t/h of coal sized between 1/2 in (12.7 mm) and 1/2 mm. See also: centrifugal separation; cyclone.


Steel produced by blowing iron-ore powder into a hot gas.


A series of beds deposited during a single sedimentary cycle of the type that prevailed during the Pennsylvanian period. The cyclothem, which ideally consists of 10 members (in western Illinois, the fifth member is a coal layer), indicates an unstable coastal environment in which marine submergence and emergence occurred. A cyclothem ranks as a formation in the scale of stratigraphic nomenclature. Syn: coal-measures unit.


A particle accelerator in which charged particles receive repeated synchronized accelerations by electrical fields as the particles spiral outward from their source. The particles are kept in the spiral by a powerful magnet.

cylinder cuts

In cylinder cuts the blasting is performed toward an empty hole in such a way that, as the charges in the first, second, and subsequent holes detonate, the broken rock is thrown out of the cut. The opening is successively and uniformly (cylindrically) enlarged in its entire length.

cylindrical drum

See: parallel drum.

cylindrical land

Land having zero relief.

cylindrical mill

See: tube mill.

cylindrical structure

A vertical structure in sandstone, a few centimeters to several decimeters in diameter and several decimeters in length, with a structureless interior, attributed to a rising water column or a spring channel. Syn: sandstone pipe.


A triclinic mineral, Pb (sub 4) FeSn (sub 4) Sb (sub 2) S (sub 16) ; forms cylinders that separate under pressure into distinct shells or folia, or is massive; at Poopo, Bolivia.

cylindroconical drum

A combination of a cone and a cylinder. The ascending rope is wound on the smaller diameter of the cone; as the engine reaches full speed after the period of acceleration, the rope is wound on the larger cylindrical part. For deep shafts the rope is wound back on itself for the last part of the hoisting period, thus reducing the width of the drum. See also: bicylindroconical drum.

cymoid loop

The splitting of a vein along its dip or strike into two branches, both of which curve away from the general trend and then unite to resume a direction parallel to but not in line with the original trend. See also: cymoid structure.

cymoid structure

A vein, or a vein-shaped structure, shaped like a reverse curve. See also: cymoid loop.


See: cat's-eye; chrysoberyl.


A monoclinic mineral, BaAl (sub 2) Si (sub 2) (O,OH) (sub 8) .H (sub 2) O; pseudohexagonal; at the Benalt manganese mine, Wales. Named from Cymru, the Welsh name for Wales.


A variety of vesuvianite or idocrase, of a blue tint, which is supposedly due to copper.

cypritic steel

A steel containing approx. 15% chromium and 9% copper; claimed to be resistant to corrosion in the atmosphere and to tap water, but its corrosion-resistant properties are inferior to the conventional austenitic chromium-nickel steels of the 18-8 type.


A tetragonal mineral, NaFe (sub 3) (PO (sub 4) ) (sub 2) (OH) (sub 4) .2H (sub 2) O ; in pegmatite at Cyrilov, Moravia, Czech Republic.


A variety of zircon.

Czochralski's reagent

An etchant for iron or steel, consisting of a solution of 10% to 20% ammonium persulfate in water.

Czochralski technique

A method of growing single crystals of refractory oxides, and of other compounds, by pulling from the pure melt; the compound must melt congruently.