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

Definition from Wiktionary, the free dictionary
Jump to navigation Jump to search


A compartment for the driver in a mine locomotive, continuous mining machine, shuttler car, scoop, etc. All coal mine locomotives in excess of 10 st (9 t) weight must have a cab at each end or an adequate center cab.

caballa ball

Eng. Ironstone nodule worked for iron in the Weald. Also called bulls. See also: ballstone; bears' muck; mare ball.

cab guard

On a dump truck, a heavy metal shield extending up from the front wall of the body and forward over the cab.


a. A heavy multiple-strand steel rope used in cable-tool drilling as the line between the tools and the walking beam. Syn: drilling cable.

b. A term used loosely to signify a wire line. See also: wire line. c. A fiber cable consists of three hawsers laid up left-handed. See also: wire rope; cable-laid rope. d. A ropelike, usually stranded assembly of electrical conductors or of groups of two or more conductors insulated from each other but laid up together usually by being twisted around a central core, the whole usually heavily insulated by outside wrappings; specif., a submarine cable. e. A steel rope for hoisting or for aerial trams. f. A flexible rope composed of many steel wires or hemp fibers in groups, first twisted to form strands, several of which are again twisted together to form a rope. Also called wire cable; wire line; wire rope; steel cable. See also: wire-line cable. g. See: armored cable; electric cable. h. A single concentration of steel wire intended for prestressing. i. A nautical unit of horizontal distance, equal to 600 ft (100 fathoms; 182.9 m) and approx. 0.1 nmi (0.18 km).

cable belt conveyor

A conveyor using steel wire ropes to take the tensile pull, which in a conventional conveyor is taken by the belt. Two-stranded steel ropes, one on either side of the conveyor, are used for this purpose. The belt sits on and is supported across the two ropes by means of rubber shoe forms along the belt edges. These belts can be of long lengths, high capacities, and high lifts.

cable bolt

A device or method for reinforcing ground prior to mining. The basic cable bolt support consists of a high-strength cable installed in a borehole 4.12 to 6.35 cm in diameter and grouted with cement. Syn: cable tendon; cable dowel.

cable bolting

Complex electrical plugs and sockets used throughout a mine distribution system to connect mobile machinery to trailing cables, to connect cables with one another, and to connect cables to power centers, switchhouses, and substations.

cable control unit

A high-speed tractor winch having one to three drums under separate control. Used to operate bulldozers and towed equipment.

cable dowel

See: cable bolt.

cable drill

a. A heavy drilling rig in which a rope is used for suspending the tools in the borehole. See also: churn drill.

b. A churn or percussion drill rig, consisting of a tower (derrick), wire rope for moving tools vertically, a power unit, and a reciprocating device. It drills holes of up to 10 in (25.4 cm) in diameter vertically to considerable depths.

cable excavator

A long-range, cable-operated machine that works between a head mast and an anchor.

cable hook

A round hook with a wide beveled face.

cable-laid rope

a. A compound-laid rope consisting of several ropes or several layers of strands laid together into one rope, as, for instance, 6 by 6 by 7.

b. A rope in which both the fibers forming the strands and the strands themselves are twisted to the left. c. Wire cable made of several ropes twisted together; strands of hawser-laid rope, twisted right-handed together without limitation as to the number of strands or direction of twist. A fiber cable-laid rope is composed of three strands of hawser-laid rope, twisted right-handed.

cable railway

An inclined track up and down which wagons travel fixed at equal intervals to an endless steel wire rope, either above or below the wagons.

cable reel

A drum on which conductor cable is wound, including one or more collector rings and associated brushes, by means of which an electric circuit is made between the stationary winding on the locomotive or other mining device and the trailing cable that is wound on the drum. The drum may be driven by an electric motor, by a hydraulic motor, or mechanically from an axle on the machine.

cable-reel locomotive

A face or gathering locomotive driven by a power cable connected to trolley wires. The cable winds on a reel attached to the locomotive.

cable-screw conveyor

A one-way or closed-circuit conveyor powered by a flexible, torque-transmitting cable of which helical (screw) threads are an integral part. Loads or load carriers engage the thread and advance a distance equal to one pitch each revolution of the cable screw.

cable selvage belt

A conveyor belt in which the carrying section is composed of rubber and fabric with attached intermittent transverse metal supports having both ends supported by cables. The cables transmit the driving force, and the center portion functions as the load-supporting medium.

cable shield

A metallic shield consisting of nonmagnetic material applied over the insulation of the individual conductors or conductor assembly.

cable splice kit

A short piece of tubing or a specially formed band of metal generally used without solder in joining ends of portable cables for mining equipment.

cable system

One of the well-known drilling systems, sometimes designated as the American or rope system. The drilling is performed by a heavy string of tools suspended from a flexible manila or steel cable to which a reciprocating motion is imparted by an oscillating "walking beam" through the suspension rope or cable. See also: churn drill.

cable-system drill

See: churn drill.

cable tendon

See: cable bolt.

cable-tool cuttings

The rock fragments and sludge produced in drilling a borehole with a churn drill.

cable-tool dresser

See: tooldresser.

cable-tool drill

See: churn drill; percussion drill.

cable-tool drilling

A method of drilling, now largely replaced by rotary drilling, in which the rock at the bottom of the hole is broken up by a steel bit with a blunt, chisel-shaped cutting edge. The bit is at the bottom of a heavy string of steel tools suspended on a cable that is activated by a walking beam, the bit chipping the rock by regularly repeated blows. The method is adapted to drilling water wells and relatively shallow oil wells.

cable tools

The bits and other bottom-hole tools and equipment used to drill boreholes by percussive action, using a rope, instead of rods, to connect the drilling bit with the machine on the surface. See also: churn drill.


A system in which the carriers are supported by a cable and are not detached from the operating span. The travel of the carriers is wholly within the span. See also: aerial cableway.

cableway excavator

A slackline cableway used for excavating a restricted area.

cableway transporter

A transporter crane on which the track for the carrier is a steel wire rope.


a. An unfaceted cut gemstone of domed or convex form. The top is smoothly polished; the back, or base, is usually flat or slightly convex, may be concave, and is commonly unpolished. The girdle outline may be round, oval, square, or any other shape.

b. The style of cutting such a gem. c. A polished but uncut gem. See also: en cabochon.


A hydrous arsenate of nickel, cobalt, and magnesium; possibly magnesian annabergite.


See: cacholong.


Fr. The place where provisions, safety or rescue equipment, ammunition, etc., are cached or hidden by trappers, miners, or prospectors, in unsettled regions.


An opaque or feebly translucent, bluish-white, pale-yellowish, or reddish variety of common opal containing a little alumina. Syn: cachalong; pearl opal.


An orthorhombic mineral, (Fe,Al) (sub 25) (PO (sub 4) ) (sub 17) O (sub 6) (OH) (sub 12) .75H (sub 2) O .

cactus grab

A digging and unloading attachment hung from a crane or excavator. It consists of a split and hinged bucket fitted with curved jaws or teeth which dig into the loose rock while the bucket is being dropped and contract to lift the load while it is being raised. It is used increasingly for mechanical mucking in shaft sinkings. See also: hoppit.


See: xenocryst. Also spelled chadacryst.

cadastral control

A system of established monuments whose positions are accurately determined and are used in all correlated cadastral surveys.

cadastral map

A large-scale map showing the boundaries of subdivisions of land, usually with the directions and lengths thereof and the areas of individual tracts, compiled for the purpose of describing and recording ownership. It may also show culture, drainage, and other features relating to use of the land.

cadastral survey

Survey relating to land boundaries and subdivisions, made to create or to define the limitations of a title, and to determine a unit suitable for transfer. Includes surveys involving retracements for the identification, and resurveys for the restoration, of property lines. (The term "cadastral" is practically obsolete; may be found in older historical records; current usage is "land survey" or "property survey.")


A little pocket oilcan for miners.


a. An impure zinc oxide that forms on the walls of furnaces in the smelting of ores containing zinc. See also: furnace cadmium.

b. The chemical compound CdO. c. See: calamine.


A soft, bluish-white metal, similar in many respects to zinc, copper, and lead ores. Almost all cadmium is obtained as a byproduct in the treatment of these ores. Symbol, Cd. Used in electroplating, in solder, for batteries, as a barrier to control atomic fission, and in TV tubes. Cadmium and solutions of its compounds are toxic.

cadmium blend

The mineral greenockite, CdS . Also called cadmium ocher.

cadmium columbate

Cd (sub 2) Cb (sub 2) O (sub 7) is an antiferroelectric and has low losses at high frequency. Syn: cadmium niobate.

cadmium niobate

Cd (sub 2) Nb (sub 2) O (sub 7) ; a ferroelectric compound of potential value as a special electroceramic; the Curie temperature is -103 degrees C. See also: cadmium columbate.

cadmium ocher

The mineral greenockite; used as a pigment.


A hexagonal mineral, CdSe ; wurtzite structure; resinous to adamantine; black; perfect cleavage; forms fine xenomorphic disseminations cementing sandstone. Also spelled kadmoselite.


Said of an igneous rock or magma that contains calcium, iron, and magnesium. Etymol: a mnemonic term derived from calcium + ferric (or ferrous) + magnesium + ic.


A vertically moving enclosed platform used in a mine shaft for the conveyance of workers and materials, usually designed to take one or two cars per deck and may be single or multidecked.

cage bar

Safety device that holds doors shut or keeps trams in position.

cage chain

See: bridle chain.

cage cover

See: bonnet.

cage guide

Conductor made of wood, iron or steel, or wire rope; used to guide the cages in the shaft and to prevent them from swinging and colliding with each other while in motion. See also: guides; fixed guides; rope guide.

cage mill

Also known as a disintegrator; used for secondary crushing of stone and gravel, and for reduction of slag, fertilizers, etc.


a. One who directs station operations and movement of cages used to raise and lower workers, mine cars, and supplies between various levels and surface; works at the top of a shaft or at an intermediate level inside a mine. Also called cageman; cage tender; shaft headman; skip tender. See also: banksman; hitcher; top cager; onsetter.

b. A power-operated ram for pushing mine cars into or out of cages at the pit top or pit bottom. c. One who supervises weighing and the sequence of sending up components of a furnace charge, keeps tally of the number of charges, and signals to the top filler when it is time to hoist.

cager coupler

In bituminous coal mining, one who works with a cager, coupling and uncoupling cars at a shaft station.

cage seat

Scaffolding, sometimes fitted with strong springs, to take the shock, and on which the cage rests when reaching the pit bottom or other landing.

cage sheet

Short prop or catch on which a cage stands during caging or changing cars.

cage shoe

One of the fittings bolted to the side of a cage to engage the rigid guides in a shaft. Usually there are two for each guide, one at the top and one at the bottom of the cage. The shoes are usually about 1 ft (0.3 m) long and shaped to fit closely around about three-quarters of the guide, with sufficient clearance for free movement but not sufficient to allow the shoe to come off the guide.

cage stop

Equipment fitted on the cage floor to hold the car in position while traveling in the shaft. Spring- or rubber-mounted stops are commonly used. See also: kep.


A baguette; an oblong cut diamond.


A tetragonal mineral, Ca (sub 2) B(AsO (sub 4) )(OH) (sub 4) ; forms white sphenoidal crystals.


See: Cenozoic.


An artificial mound of rocks, stones, or masonry, usually conical or pyramidal, used in surveying to aid in the identification of a point or boundary.


Smoky-yellow or brown varieties of quartz, the coloring matter probably due to some organic compound; named from Cairngorm in the Scottish Grampians; the more attractively colored varieties are used as semiprecious gem stones. Also called smoky quartz, smokestone.

caisson drill

In sampling placer deposits, a caisson drill is driven by a combination of rotational impact and the weight of the drilling equipment.

caisson sinking

A method of sinking a shaft through wet clay, sand, or mud down to firm strata. Cast-iron tubbing, attached ring by ring on the surface, is gradually lowered as the shaft is excavated. There is a special airtight working chamber at the bottom of the lining. A cutting shoe at the lower end of the tubbing helps it to penetrate the soft ground. The caisson method is obsolescent, being replaced by the freezing method, etc. See also: concrete caisson sinking. Also called drum shaft; drop shaft.


a. See: box canyon.

b. A defile leading up to a mountain pass; also, the pass itself. Etymol: Spanish cajon, large box. The term is used in the Southwestern United States.


a. The solid residue left in a filter press or on a vacuum filter after the solution has been drawn off.

b. Solidified drill sludge. c. That portion of a drilling mud adhering to the walls of a borehole. Syn: wall cake. d. See: cake of gold; mud cake. e. To form in a mass such as when ore sinters together in roasting, or coal cakes together in coking.

cake copper

Copper cast in a round, cake-shaped mass. See also: tough cake.

caked dust

Dust particles with sufficient cohesion that a light stroke with a brush or a light airblast, such as from the mouth, will not cause the dust to be dispersed.

cake of gold

Gold formed into a compact mass (though not melted) by distillation of mercury from amalgam. Also called sponge gold. Syn: cake.

cake thickness

The measure of the thickness of the filter cake deposited against a porous medium. Cake thickness and water loss constitute the determining factors of filtration qualities.

caking coal

Coal that softens and agglomerates on heating and after volatile matter has been driven off at high temperatures; produces a hard gray cellular mass of coke. All caking coals are not good coking coals. See also: coking coal.

caking index

A laboratory method of indicating the degree of caking, coking, or binding together of a coal when a sample is heated in a prescribed manner. Syn: agglutinating power.


Panning tin gravels in a half-calabash gourd. Used in prospecting and alluvial mining in primitive conditions.


See: turquoise.


N. of Eng. Red or mottled Paleozoic marls and shales. Also called calaminker. See also: symon. CF: whintin.


a. A commercial, mining, and metallurgical term for the oxidized ores of zinc (including silicates and carbonates), as distinguished from the sulfide ores of zinc. Syn: cadmia. See also: electric calamine.

b. A former name for hemimorphite. c. In Great Britain, a name used for smithsonite. See also: smithsonite. d. A former name for hydrozincite. e. A special kind of so-called galvanized iron. Also spelled kalamin. Syn: galmei.

calamine stone

Eng. A carbonate of zinc; smithsonite.

calamine violet

An indicator plant which grows only on zinc-rich soils in the zinc districts of Central and Western Europe.


An asparagus-green variety of tremolite.


A monoclinic mineral, 2[AuTe (sub 2) ] ; brittle: commonly contains silver; sp gr, 9.35; an important source of gold.


Prefix meaning containing calcium carbonate.


a. Said of a series of igneous rocks in which the weight percentage of silica is between 56 and 61 when the weight percentages of CaO and of K (sub 2) O + Na (sub 2) O are equal.

b. Said of an igneous rock containing plagioclase feldspar.


A limestone consisting predominantly (more than 50%) of recycled calcite particles of sand size; a consolidated calcareous sand. CF: calcareous sandstone.


Said of a substance that contains calcium carbonate. When applied to a rock name, it implies that as much as 50% of the rock is calcium carbonate.

calcareous crust

An indurated soil horizon cemented with calcium carbonate; caliche.

calcareous dolomite

A carbonate rock containing 50% to 90% dolomite. (Leighton & Pendexter, 1962) CF: calcitic dolomite.

calcareous dust

Limestone, quicklime, hydrated lime, and cement dusts fall in this class. These dusts are more or less soluble in the body fluids, and are eventually absorbed.

calcareous ooze

A deep-sea pelagic sediment containing at least 30% calcareous skeletal remains; e.g., pteropod ooze. CF: siliceous ooze.

calcareous ore

Ore in which the gangue consists mainly of carbonate of lime.

calcareous peat

See: eutrophic peat.

calcareous rock

See: carbonate rock.

calcareous sandstone

a. A sandstone cemented with calcite.

b. A sandstone containing appreciable calcium carbonate, but in which clastic quartz is present in excess of 50%. CF: calcarenite.

calcareous sinter

See: travertine.

calcareous spar

Coarsely crystalline calcium carbonate. See also: calcite.

calcareous tufa

See: tufa.


Adj. Designates the calcium carbonate cement of a sedimentary rock.


Rock consisting of both calcite and dolomite crystals.


Native calcium oxide, CaO, found on Mount Vesuvius, Italy. It formed from limestone enveloped in lava and altered by the heat of the lava.


See: chalcedony.


A fine-grained calc-silicate rock of flinty appearance formed by thermal metamorphism of a calcareous mudstone, possibly with some accompanying pneumatolytic action. See also: calc-silicate hornfels.


See: calcic.


Calcium borate, CaB (sub 2) O (sub 4) , monoclinic. White radial aggregates in drill cores from limestone skarn, from the Ural Mountains. Named from the composition. See also: frolovite.


Said of minerals and igneous rocks containing a relatively high proportion of calcium; the proportion required to warrant use of the term depends on circumstances. Said of a series of igneous rocks in which the weight percentage of silica is greater than 61 when the weight percentages of CaO and of K (sub 2) O + Na (sub 2) O are equal. Syn: calcian.


See: anorthite.


Capable of being calcined or reduced to a friable state by the action of fire.


a. The heating of a substance to its temperature of dissociation; e.g., of limestone to CaO and CO (sub 2) or of gypsum to lose its water of crystallization.

b. Heating ores, concentrates, precipitates, or residues to decompose carbonates, hydrates, or other compounds. CF: roasting. c. Heating metals at high temperatures to convert them into their oxides.


a. Ore or concentrate after treatment by calcination or roasting and ready for smelting.

b. By heating, to expel volatile matter as carbon dioxide, water, or sulfur, with or without oxidation; to roast; to burn (said of limestone in making lime).

calcined gypsum

Gypsum partially dehydrated by means of heat, having the approximate chemical formula, CaSO (sub 4) .�H (sub 2) O .


See: calcining furnace.


a. Roasting of ore in oxidizing atmosphere, usually to expel sulfur or carbon dioxide. If sulfur removal is carried to practical completion, the operation is termed sweet roasting; if CO (sub 2) is virtually removed, dead roasting.

b. Reducing to powder by heating.

calcining furnace

A furnace or kiln in which ores or metallurgical products are calcined. Syn: calciner.


An orthorhombic mineral, CaB (sub 2) O (sub 4) ; in white radial aggregates in drill cores from limestone skarn in the Urals, Russia.


A variety of celestite containing calcium.


A monoclinic mineral, Ca (sub 4) Fe(Fe,Al) (sub 4) (PO (sub 4) ) (sub 6) (OH) (sub 4) .13H (sub 2) O ; occurs in scales and nodules.


See: tyuyamunite.


An orthorhombic mineral, CaCu(VO (sub 4) )(OH) ; adelite group; moderately radioactive; in the Colorado Plateau in sandstone associated with carnotite and tyuyamunite, or in the oxidized zone of deposits containing vanadium minerals.


See: calc-silicate marble.


A limestone consisting predominantly of detrital calcite particles of silt size; a consolidated calcareous silt.


a. A trigonal mineral, 4[CaCO (sub 3) ] ; has prolific crystal habits, rhombohedral cleavage; defines hardness 3 on the Mohs scale; effervesces readily in dilute hydrochloric acid; a common and widely distributed rock-forming, authigenic, biogenic, and vein mineral; raw material for Portland cement, agricultural lime, flux for ore reduction, dimension stone, and concrete aggregate; the major mineral in limestone, marble, chalk, spongy tufa, cave deposits, and carbonatite; a cementing mineral in many clastic sedimentary rocks; a minor mineral in some silicate igneous and metamorphic rocks. Coarsely crystalline varieties are called nailhead spar, dogtooth spar (acute scalenohedra), and Iceland spar (optical-grade crystals). Abbrev.: Cc. CF: dolomite. Syn: carbonate of calcium; calcspar.

b. The mineral group calcite, gaspeite, magnesite, otavite, rhodochrosite, siderite, smithsonite, and sphaerocobaltite

calcite limestone

A limestone containing not more than 5% of magnesium carbonate.

calcite marble

A crystalline variety of limestone containing not more than 5% of magnesium carbonate.

calcitic dolomite

A dolomite rock in which calcite is conspicuous, but the mineral dolomite is more abundant; specif. a dolomite rock containing 10% to 50% calcite and 50% to 90% dolomite, or a dolomite rock whose Ca/Mg ratio ranges from 2.0 to 3.5. CF: dolomitic limestone.


A rock composed of calcite; e.g., limestone.


a. The act or process of forming calcite, such as by alteration of aragonite.

b. The alteration of existing rocks to limestone, due to the replacement of mineral particles by calcite; e.g., of dolomite in dolomite rocks or of feldspar and quartz in sandstones.


Refractory; said of certain ores.


A metallic element of the alkaline-earth group; never found in nature uncombined, occurs abundantly as limestone (CaCO (sub 3) ), gypsum (CaSO (sub 4) . 2H (sub 2) O), and fluorite (CaF (sub 2) ). Symbol, Ca. Used as a reducing agent, deoxidizer, desulfurizer, or decarburizer for alloys; as quicklime (CaO), it is the great cheap base of the chemical industry with countless uses.

calcium autunite

Artificially prepared autunite in which calcium can be replaced by Na, K, Ba, Mn, Cu, Ni, Co, and Mg. Syn: autunite.

calcium carbide

CaC (sub 2) ; produced commercially by heating quicklime and carbon together in an electric furnace. Used for the generation of acetylene and for making calcium cyanamide.

calcium carbonate

a. White powder or colorless crystals; CaCO (sub 3) . One of the most stable, common, and widely dispersed of materials. It occurs in nature as aragonite, calcite, chalk, limestone, lithographic stone, marble, marl, and travertine. Referred to as whiting, it has many uses in ceramics to introduce calcium oxide (CaO). Also used as a separator in glass firing.

b. Calcium carbonate (molecular weight, 100.09) crystallizes in two crystal systems: hexagonal rhombohedral or hexagonal as calcite, and orthorhombic as aragonite. Hexagonal calcium carbonate (calcite) is colorless, white, yellowish, or rarely pale gray, red, green, blue, or violet; sp gr, 2.710 (at 18 degrees C); Mohs hardness, 3; melting point, 1,339 degrees C (at 1,025 atm); decomposes at 898.6 degrees C; and soluble in water, in acids, and in ammonium chloride solution. Orthorhombic calcium carbonate (aragonite) is colorless, white, yellow, reddish, bluish, or black; sp gr, 2.93, ranging from 2.85 to 2.94; Mohs hardness, 3.5 to 4.0; transforms to calcite at 520 degrees C; decomposes at 825 degrees C; and soluble in water, in acids, and in ammonium chloride solution. c. Source of quicklime and of calcium metal.

calcium chloride process

A method used to consolidate floor dust in mine roadways in which calcium chloride is applied with a wetting agent.

calcium feldspar

See: anorthite.

calcium mica

See: margarite.

calcium minerals

Naturally abundant and widely exploited in industry. Main useful ores are calcite, dolomite, anhydrite, and gypsum. Apatite is mined for phosphorus; fluorite for fluorides; and colemanite and ulexite for boron.

calcium montmorillonite

An artificially prepared clay mineral with calcium in place of magnesium.

calcium phosphate

See: apatite.

calcium plagioclase

See: anorthite.


See: autunite.


a. Conglomerate consisting of surficial sand and gravel cemented into a hard mass by calcium carbonate precipitated from solution and redeposited through the agency of infiltrating waters, or deposited by the escape of carbon dioxide from vadose water.

b. A calcareous duricrust; caliche. Etymol: "cal"careous + con"crete." CF: silcrete; ferricrete.


A deposit composed of sapropel (dominant) and remains of calcareous algae.


A metamorphosed argillaceous limestone with a schistose structure produced by parallelism of platy minerals.

calc-silicate hornfels

A fine-grained metamorphic rock containing a high percentage of calc-silicate minerals. See also: calc-flinta; hornfels; limurite; skarn; tactite.

calc-silicate marble

A marble in which calcium silicate and/or magnesium silicate minerals are conspicuous. Syn: calciphyre.

calc-silicate rock

A metamorphic rock consisting mainly of calcium-bearing silicates, such as diopside and wollastonite, and formed by metamorphism of impure limestone or dolomite; associated with skarn-type mineral deposits. Syn: lime-silicate rock.


See: travertine.


Coarsely crystalline calcite. Also spelled: calc-spar. See also: calcite. Syn: calcareous spar.


See: tufa.


A secondary mineral, Ca(UO (sub 2) ) (sub 3) (MoO (sub 4) ) (sub 3) (OH) (sub 2) .11H (sub 2) O .

Caldecott cone

A conical tank used to settle and discharge as a continuous underflow the relatively coarse sand from an overflowing stream of mineral pulp. See also: cone classifier; Callow cone.


A large, basin-shaped volcanic depression, more or less circular, the diameter of which is many times greater than that of the included vent or vents, no matter what the steepness of the walls or the form of the floor may be. CF: crater.


An isometric mineral, (Mn,Ca)(Fe,Al) (sub 2) (SiO (sub 4) ) (sub 3) ; the dark reddish-brown manganese-iron end member of the garnet group.


See: bell mold; caldron bottom; kettle bottom.

caldron bottom

a. Mud-filled prostrate trunk of sigillaria in the roof of certain coal seams. The trunk is a separate mass of rock, with a film of coal around it. It is liable to collapse without any warning sound. Also called horseback. Syn: caldron; kettle bottom. See also: pot.

b. Eng. A cone-shaped mass with slippery surfaces found in the roof of some seams. It sometimes comprises a ring of coal around a core of material differing slightly from the ordinary roof. CF: pot bottom. Also called pothole.


An orthorhombic mineral, Pb (sub 5) Cu (sub 2) (CO (sub 3) )(SO (sub 4) ) (sub 3) (OH) (sub 6) ; green (not to be confused with celadonite).

calf reel

The churn-drill winch used for handling casing and for odd jobs. Also called casing reel.


a. A term applied broadly in the Southwestern United States (esp. Arizona) to a reddish-brown to buff or white calcareous material of secondary accumulation; commonly found in layers on or near the surface of stony soils of arid and semiarid regions, but also occurring as a subsoil deposit in subhumid climates. It is composed largely of crusts of soluble calcium salts in addition to such materials as gravel, sand, silt, and clay. It is called hardpan, calcareous duricrust, or calcrete in some localities, and kankar in parts of India. Syn: calcareous crust; tepetate. ---Etymol: American Spanish, from a Spanish word for almost any porous material (such as gravel) cemented by calcium carbonate.

b. Gravel, rock, soil, or alluvium cemented with soluble salts of sodium in the nitrate deposits of the Atacama Desert of northern Chile and Peru; it contains sodium nitrate (14% to 25%), potassium nitrate (2% to 3%), sodium iodate (up to 1%) sodium chloride, sodium sulfate, and sodium borate, mixed with brecciated clayey and sandy material in beds up to 2 m thick. c. A term used in various geographic areas for a thin layer of clayey soil capping a gold vein (Peru); whitish clay in the selvage of veins (Chile); feldspar, white clay, or a compact transition limestone (Mexico); a mineral vein recently discovered, or a bank composed of clay, sand, and gravel in placer mining (Colombia). The term has been extended by some authors to quartzite and kaolinite.


Mex. Silver ore, generally colored with some iron sulfate, the result of weathering.

California poppy

A local indicator plant for copper in Arizona, observed over the outcrop of the San Manuel copper deposit. Here the distribution of this species is confined to copper-rich soil, and its population density is closely proportional to the copper content of the soil.

California-type drag head

A device for sand dredging; the drag has a hinged afterbody that adjusts to the angle of the drag arm, which may vary with the depth of water.

California-type dredge

A single-lift dredge with stacker. Buckets, which are closely spaced, deliver to a trommel. The oversize is piled behind the dredge by a conveyor (stacker). Undersize is washed on gold-saving tables on the deck; tailings discharge astern through sluices.


a. A compact, massive, translucent to opaque variety of vesuvianite; typically dark-green, olive-green, or grass-green, commonly mottled with white or gray, closely resembling jade; an ornamental stone. Principal sources are Fresno, Siskiyou, and Tulare Counties, CA. Syn: American jade.

b. A white variety of grossular garnet from Fresno County, CA.


a. An instrument used to measure precisely the thickness or diameter of objects or the distance between two surfaces, etc.

b. An instrument used in conjunction with a microlog which, when lowered down a borehole, measures and records the internal diameter throughout its depth. c. An instrument consisting of a graduated beam and at right angles to it a fixed arm and a movable arm which slides along the beam to measure the diameter of logs and trees.

caliper brake

Brake in which two brakeshoes are curved to the brake path and anchored near the centerline of the drum.

caliper log

A well log that shows the variations with depth in the diameter of an uncased borehole. It is produced by spring-activated arms that measure the varying widths of the hole as the device is drawn upward. Syn: section-gage log.


a. A heat-resistant alloy of aluminum, nickel, and iron.

b. Iron or steel treated by calorizing.


a. To drive tarred oakum into the seams between planks and fill with pitch.

b. Limestone or chalk; also spelled caulk. c. A variety of barite. d. To peen and draw metal toward and around a diamond being hand-wet in a malleable-steel bit blank. Also called peen. Syn: peeler. e. To wick.


An orthorhombic mineral, (Ce,La) (sub 2) (CO (sub 3) ) (sub 3) .4H (sub 2) O ; pale yellow; a source of rare-earth elements.


A monoclinic mineral, Cu (sub 2) Mg (sub 2) (CO (sub 3) )(OH) (sub 6) .2H (sub 2) O ; azure-blue.


An apple- to emerald-green, massive, waxlike phosphate, possibly a mixture of wavellite and turquoise.


Lanc. A shaly coal.

Callon's rule

A rule stating that when a pillar has to be left in an inclined seam for the support of a shaft or of a surface structure, a greater width should be left on the rise side of the shaft or structure than on the dip side.

Callow cone

A conical free-settling tank. Pulp is fed centrally; the finer solid fraction overflows peripherally, and the coarser fraction is withdrawn at a controlled rate via the apex at the cone's bottom. See also: Caldecott cone; cone classifier.

Callow flotation cell

An early form of pneumatic flotation cell, still in limited use. Air is blown in at the bottom of the tank at low pressure, through a porous septum such as a blanket, and mineralized froth overflows along the sides while the tailings progress to the discharge end.

Callow screen

A continuous belt formed of fine screen wire travels horizontally between two drums. Pulp, fed from above, flows through together with the finer solids, while coarser material is discharged as the screen passes over the end drum.


A tetragonal mineral, 2[Hg (sub 2) Cl (sub 2) ] ; a secondary alteration of mercury-bearing minerals. Syn: calomelite; calomelano; horn quicksilver; mercurial horn ore.


See: calomel.

calomel electrode

Half-cell used to measure electromotive force; potential being that of mercury and mercurous chloride in contact with saturated solution of potassium chloride. Used in pH measurement.


See: calomel.


The phenomenon of glowing when a substance is stimulated by heat rays that lie beyond the red end of the visible spectrum. See also: thermoluminescence.


The gram calorie (or small calorie) is the quantity of heat required to raise the temperature of 1 g of water from 15 to 16 degrees C. The mean calorie is one-hundredth part of the heat required to raise 1 g of water from 0 to 100 degrees C. CF: heat unit.

calorific intensity

The temperature of a fuel attained by its combustion.

calorific power

The quantity of heat liberated when a unit weight or a unit volume of a fuel is completely burned.

calorific value

See: gross calorific value; net calorific value.


Any apparatus for measuring the quantity of heat generated in a body or emitted by it, such as by observing the quantity of a solid liquefied or of a liquid vaporized under given conditions. Used in determining specific heat; latent heat; the heat of chemical combinations; etc.

calorimeter room

A place at the surface of a mine where drained combustible gases are monitored or their heat content is ascertained.


A process of rendering the surface of steel or iron resistant to oxidation by spraying the surface with aluminum and heating to a temperature of 800 to 1,000 degrees C.


An orthorhombic mineral, Cu(OH,Cl) (sub 2) .2H (sub 2) O ; in azure-blue spherules and sheaves of scales having good basal cleavage; at the Calumet Mine, Calumet, MI. Named from the locality. CF: anthonyite.


The friable residue (as a metal oxide) left when a mineral or metal has been subjected to calcination or roasting; e.g., lime from calcium carbonate.


a. A steel tube attached to the upper end of a core barrel and having the same outside diameter as the core barrel. The upper end is open except for two web members running from the inside of the tube to a ring encircling the drill rod. The calyx serves as a guide rod and also as a bucket to catch cuttings that are too heavy to be flushed out of the borehole by the circulation fluid. Syn: bucket; sludge barrel; sludge bucket.

b. Syn: shot drill. c. A pipe or tube equipped with a sawtooth cutting edge, sometimes used to obtain a core sample of a formation being drilled. CF: basket. d. In well drilling, a long cylindrical vessel that guides an annular toothed bit. Its action is like that of a diamond drill. A toothed cutter takes the place of a diamond crown and is rotated by hollow flushing rods with a strong constant flow of water. A core is cut, preserved in a core barrel, and brought to the surface. The drills are made large enough so that the holes are used as shafts. e. See: sediment tube.

calyx boring

a. The process of drilling with a shot drill.

b. The hole or core produced by this process.

calyx drill

A rotary core drill that uses hardened steel shot for cutting rock, which will drill holes from diamond-drill size up to 6 ft (1.8 m) or more in diameter. Drilling is slow and expensive, and holes cannot be drilled more than 35 degrees off the vertical, as the shot tends to collect on the lower side of the hole. Also called shot drill. See also: core drill.


A beam, bar, or girder bent like a bow, with the hump towards the strata.


The oldest of the systems into which the Paleozoic stratified rocks are divided; also, the corresponding oldest period of the Paleozoic era.

camel back

A miner's term sometimes applied to such structures as bells, pots, kettle bottoms, or other rock masses that tend to fall easily from a mine roof. See also: pot bottom; tortoise.

camera lucida

Mirror or prism attached to the eyepiece of a microscope, enabling an observer to sketch the object displayed.

Cammett table

A side-jerk concentrating table similar to the Wilfley table.


The substitution for a common element in a crystal lattice by a trace element of the same valence. CF: admittance; capture.


a. A cavity formed in a borehole by the detonation of an explosive charge placed in it. Also called chamber. See also: spring; socket.

b. A quarry blasting hole enlarged by chambering.


a. The period during which a furnace is continuously in operation.

b. The working life of a tank or other melting unit between major cold repairs.


A lamprophyre, similar in composition to nepheline diorite, being composed essentially of plagioclase (usually labradorite) and brown hornblende (usually barkevikite).


A yellowish to brown variety of mimetite crystallizing in barrel-shaped forms. A source of lead. See also: mimetite.


In stamp milling, a strong horizontal revolving shaft to which a number of cams are attached in such a manner that no two of them strike the tappets at the same instant, thus distributing the weight to be lifted.

cam stick

In stamp battery crushing, a square-sectioned wooden stick greased on the underside and leather-lined above; it is inserted between cam and tappet.


a. A term used in the tristate zinc and lead district for a bucket used in hoisting. A "can" ranges in capacity from 1,200 to 1,400 lb (544 to 635 kg).

b. In a nuclear reactor, the container in which fuel rods are sealed to protect the fuel from corrosion and prevent gaseous diffusion products from escaping into the coolant.


a. A term used in the Western United States for a ravine, glen, or narrow valley, smaller and less steep-sided than a canyon, such as the V-shaped valley of a dry river bed; a dale or open valley between mountains.

b. A term used in the Western United States for a small stream; a creek. Etymol: Spanish cana, cane, reed.

Canadian asbestos

See: chrysotile.

Canadian shield

The vast region of Precambrian rocks having an areal extent of 2 million square miles (5.2 million km (super 2) ) in eastern Canada.


a. An artificial watercourse cut through a land area for use in navigation, irrigation, etc.

b. That part of a tank leading from the relatively wide fining area to the machine. c. See: chute; ditch.

canal ray

See: positive ray.

Canamin clay

A clay consisting mainly of colloidal aluminum silicate from British Columbia, Canada.


a. Bird traditionally used for the detection of unsafe carbon monoxide or low oxygen levels in early coal mines.

b. Term used for modern, handheld, electronic air quality monitors, which replaced the use of canary birds. c. Yellow diamond.

canary ore

A yellow, earthy argentiferous lead ore, generally pyromorphite, bindheimite, or massicot, more or less impure.

canary stone

A yellow variety of carnelian.


a. A part of a bed of stone worked by quarrying.

b. Eng. Roof or floor removed to make height and side removed to make width. If above the seam, it is called a top canch; if below the seam, a bottom canch. A canch on a roadway close to the face is called a face canch; a canch on a roadway outbye is called a back canch. Also called brushing; ripping. c. The face of the roof ripping in a roadway. It follows that the canch is continually being excavated and advanced. See also: ripping face support. Also called ripping lip.


A trench with sloping sides and a very narrow bottom.


a. A hexagonal mineral, Na (sub 6) Ca (sub 2) Al (sub 6) Si (sub 6) O (sub 24) (CO (sub 3) ) (sub 2) .

b. The mineral group afghanite, cancrinite, davyne, franzinite, guiseppettite, liottite, microsommite, sacrofanite, vishnevite, and wenkite(?).


See: ceylonite.

candle coal

See: cannel coal; kennel coal.


a. The illuminating power of a standard sperm candle. Used as a measure for other illuminants.

b. The luminous flux emitted by a source of light per unit solid angle in a given direction. It is expressed in terms of the international candle and new candle.


See: cannel coal.


a. This name was first given to an isometric silver sulfogermanate, believed to be a new species, but later proved to be identical with argyrodite. The name was then withdrawn and transferred to (b).

b. An orthorhombic mineral, Ag (sub 8) SnS (sub 6) ; black; forms a series with argyrodite.

Canfield's reagent

An etchant, used for revealing phosphorus segregation in iron and steel, containing 1.5 g cupric chloride, 5 g nickel nitrate, and 6 g ferric chloride, in 12 mL hot water.


a. Braz. A tough, well-consolidated rock consisting essentially of hard blocks and fragments of the rocks of an iron formation, cemented with limonite. Where these fragments are plentiful and are derived from the hard ore outcrops, canga forms a valuable ore, which may run as high as 68% iron. Generally it is phosphoric, but there are considerable areas in which the phosphorus is below the Bessemer limit. CF: itabirite.

b. A ferruginous laterite developed from any iron-bearing rock, commonly basalt or gabbro; e.g., as used in Sierra Leone, canga is equivalent to lateritic iron ore.

can hoisting system

A method of hoisting in shallow lead-zinc mines in areas of the United States. Instead of the conventional engine house, operation is controlled at the top of the shaft. The onsetter below hooks the can on, then signals by a lamp attached to the wrist of the hoister sitting above. The can is hoisted, swinging free. At the surface a tail rope is snapped to the underside, a deflection plate is swung into place, and the can is lowered. It capsizes and discharges its load to the surge bin. The empty can is then again hoisted, freed of its tail rope, and wound down the shaft, where it is replaced by a full can.


a. A hopper-shaped truck, from which coal is discharged into coke ovens.

b. A container with a filter, sorbent, or catalyst, or combination of these items, which removes specific contaminants from the air passed through the container. Also called cartridge.


a. York. A completely cemented, compact, and fine-grained sandstone, or any fine-grained rock that is hard to drill.

b. A hard, dark gray massive rock consisting largely of ankerite, found in some Coal Measures marine beds.


a. Eng. The ocherous sediment in mine waters, being bicarbonate of iron precipitated by the action of the air.

b. Rust; verdigris, or copper rust.


See: cannel coal.

cannel coal

a. Term used for sapropelic coal containing spores, in contrast to sapropelic coal containing algae, which is termed boghead coal. Viewed microscopically, cannel coal shows no stratification. It is generally dull and has a more or less pronounced waxy luster. It is very compact and fractures conchoidally. There are transitions between cannel coal and boghead coal, and it is not possible always to distinguish macroscopically between them. Such a distinction can, however, be easily made a with microscope, except in high-rank coals. In American nomenclature, cannel coal must contain less than 5% anthraxylon. Cannel coal occurs in layers or lenses up to several centimeters in thickness. Thin seams consisting entirely of cannel coal are known. It occurs widely but in limited amounts. Syn: gayet. Analogous term is parrot coal. See also: sapropelic coal; spore coal; boghead coal.

b. A variety of bituminous or subbituminous coal of uniform and compact fine-grained texture with a general absence of banded structure. It is dark gray to black in color, has a greasy luster, and is noticeably of conchoidal or shell-like fracture. It is noncaking, yields a high percentage of volatile matter, ignites easily, and burns with a luminous smoky flame. Syn: canel; cannel; candle coal; kennel coal.

cannel shale

a. A shale in which the mineral and the organic matter are approx. in equal proportions.

b. A black shale formed by the accumulation of sapropels accompanied by a considerable quantity of inorganic material, chiefly silt and clay. Syn: bastard shale.

cannes marble

Same as griotte marble; a reddish marble with white spots formed by fossil shells (goniatites).

cannonball mill

A mill for grinding tough materials by attrition, using cannonballs in a rotating drum or chamber. See also: ball mill.

cannon shot

See: blown-out shot.


Corn. Applied to lodes containing calcium carbonate and fluorspar.


See: canyon.


Hydrated Brazilian hematite ore resulting from the weathering of itabirite.


A lever-type beam that is held down at one end, is supported near the middle, and supports a load on the other end.

cantilever crane

A transporter crane with one or both ends overhanging.

cantilever grizzly

Grizzly fixed at one end only, the discharge end being overhung and free to vibrate. This vibration of the bar is caused by the impact of the material. The disadvantage of the ordinary bar grizzly is clogging due to the retarding effect of the cross rods. This has been overcome in the cantilever grizzly by eliminating the tie rods except at the head end, where they are essential. The absence of these rods below the point of support also aids in preventing clogging because it permits the bars to vibrate in a horizontal plane, which keeps the material from wedging.


A covellite that occurs in cubes with cubic cleavage and is probably pseudomorphous after chalcopyrite that had replaced galena; from the Canton Mine, Georgia.


Usually applied to brattice cloth, which is a heavy canvas of cotton, hemp, or flax, frequently fireproofed.

canvas door

A simple square frame of about 2-in by 2-in (5.1-cm by 5.1-cm) pieces tied with diagonal strips and covered with brattice; used for deflecting air currents at inby points where the pressure is low.

canvas table

Inclined rectangular table covered with canvas. The pulp, to which clear water is added if necessary, is evenly distributed across the upper margin. As it flows down, the concentrates settle in the corrugations of the canvas. After the meshes are filled, the pulp feed is stopped, the remaining quartz is washed off with clear water, and finally the concentrates are removed (by hose or brooms).


a. A long, deep, relatively narrow steep-sided valley confined between lofty and precipitous walls in a plateau or mountainous area, often with a stream at the bottom; similar to, but larger than, a gorge. It is characteristic of an arid or semiarid area (such as the Western United States) where stream downcutting greatly exceeds weathering; e.g., the Grand Canyon.

b. Any valley in a region where canyons abound. Etymol: anglicized form of American Spanish canon. CF: canada. Syn: canon. c. A precipitous valley; a gorge. Also spelled canon. d. Mex. A mine-level drift or gallery.


a. A detonator or blasting cap.

b. To seal, plug, or cover a borehole. c. The roof or top piece in a three-piece timber set used for tunnel support. d. A piece of plank or timber placed on top of a prop, stull, or post. e. The horizontal member of a set of timber used as a roadway support. f. Another name for crown. g. Barren rock and/or soil covering an ore deposit. See also: cap rock. h. Overburden consisting of unconsolidated material overlying or covering bedrock. Also called cover; mantle. Syn: top. i. See: blue cap.


a. The capacity to store electrical energy; measured in farads, microfarads, or micro-microfarads.

b. In flotation, a property expressible by the ratio of the time integral of the flow rate of material or electric charge to or from a storage, divided by the related potential change.

capacitive control

An alternative to inductive control is to employ a capacitor in series with the choke and therefore to obtain a leading power factor for the circuit. The current in a capacitive circuit is less affected by changes in voltage than that in an inductive circuit. Therefore, should there be a sudden drop in mains voltage, the capacitively controlled lamp is less likely to be extinguished than the inductively controlled lamp.


An electric appliance or an adjustable electric appliance used in circuit with a motor to adjust the power factor.

capacitor-discharge blasting machine

A blasting machine in which electrical energy, stored in a capacitor, is discharged into a blasting circuit containing electric detonators.


a. As applied to mines, smelters, and refineries, the maximum quantity of product that can be produced in a period of time on a normally sustainable long-term operating rate--based on the physical equipment of the plant, and given acceptable routine operating procedures involving labor, energy, materials, and maintenance.

b. As applied to diamond and rotary drills, the load that the hoisting and braking mechanism of a diamond or rotary drill is capable of handling on a single line, expressed in feet or meters as the depth to which the drill can operate with different size bits. c. In ore dressing, the capacity of a screen is the measure of the amount of material that can be screened in a given time, and is typically measured in tons per square foot per hour per millimeter of aperture.

capacity factor

a. The ratio between the breaking strength of a winding rope and the load suspended on it (excluding the weight of the rope itself).

b. A method of assessing the size of a rope. The capacity factor of the rope is the static factor of safety of the rope at the capping; i.e., the breaking strength of the rope divided by the weight of the loaded cage or skip and the suspension gear comprising the chains, or equivalent equipment, and a detaching hook.

capacity load

The maximum load that can be carried safely.

capacity of the market

As applied to mining, the ability of the market to buy, esp. with regard to the quantity that can be placed in the market, and to the prices that can be obtained.

cap crimper

A mechanical device for crimping the metallic shell of a fuse detonator or igniter cord connector securely to a section of inserted safety fuse. See also: crimper.

Cape blue

Crocidolite asbestos found near Prieska, South Africa. See also: crocidolite.

cape diamond

A diamond with a yellowish tinge.


a. A wall of a lode; so called by Cornish miners, primarily where the country rock adjacent to the lode has been more or less altered by the same mineralizing agencies through which the lode was formed. Syn: carrack; cappel; capping. See also: capel lode.

b. A fitting at the end of the winding rope to enable the bridle chains of the cage to be connected by a pin through the clevis.

capel lode

Corn. A lode composed of hard unpromising feldspar containing minute particles of chlorite. See also: capel.

Cape ruby

Brilliantly red garnet, gem stone. Other varieties are carbuncle and Bohemian garnet. CF: pyrope.


a. The action by which a fluid, such as water, is drawn up (or depressed) in small interstices or tubes as a result of surface tension. Syn: capillary action.

b. The state of being capillary. c. A phenomenon observable when making borehole inclination surveys by the acid-etch method, wherein the upper surface of the acid curves upward, forming a concave surface. When the acid bottle is in a vertical or horizontal position, the concave surface is symmetrical, and the resultant etch plane is horizontal. When the bottle is tilted, the concave surface is asymmetric; the resultant etch plane is not horizontal, and the angle so indicated is always greater than the true inclination of the borehole. A capillarity correction is applied. See also: etch angle; capillarity correction. d. The action by which the surface of a liquid, where it is in contact with a solid, is elevated or depressed depending upon the relative attraction of the molecules of the liquid for each other and for those of the solid. Esp. observable in capillary tubes, where it determines the elevation or depression of the liquid above or below the level of the liquid in which the tube is dipped.

capillarity correction

The deduction of a specific angular value from the apparent angle, as indicated by the plane of the etch line in an acid-survey bottle, to correct for capillarity effects and thereby determine the true inclination angle of a borehole. Proper values to be deducted from the apparent angles read on acid bottles differing in size may be determined by referring to charts, graphs, or tables prepared for that purpose. See also: capillarity; capillarity-correction chart.

capillarity-correction chart

A chart, graph, or table from which the amount of capillarity correction may be ascertained and applied to an angle reading taken from an acid-etch line in an acid bottle of specific size to determine the true angle of inclination of a borehole surveyed by the acid-etch method. Also called correction chart; test-correction chart. See also: capillarity correction.


a. The action by which the surface of a liquid is elevated at the point at which it is in contact with a solid (such as in a lamp wick). See also: capillarity.

b. Resembling a hair; fine, minute, slender; esp., having a very small or thin bore usually permitting capillary. c. Said of a mineral that forms hairlike or threadlike crystals, e.g., millerite. Syn: filiform; moss; wire; wiry. d. Said of tubes or interstices with such small openings that they can retain fluids by capillarity.

capillary action

See: capillarity.

capillary attraction

The adhesive force between a liquid and a solid in capillarity.

capillary movement

The rise of subsoil water above the water table through the channels connecting the pores in the soil.

capillary pyrite

See: millerite.

capillary water

a. Water held in, or moving through, small interstices or tubes by capillarity. The term is considered obsolete. Syn: water of capillarity.

b. Water of the capillary fringe.

capital expenditure

The amount of money required for the purchase of the right to mine a deposit, for its preliminary development, for the purchase of adequate equipment and plant to operate it, and for working capital.

capital scrap

Scrap from redundant manufactured goods and equipment, collected and processed by merchants. See also: process scrap.

capitan limestone

Massive white limestone found in New Mexico and Texas.

cap lamp

The term generally applied to the lamp on a miner's safety hat or cap. Used for illumination only. See also: safety lamp; miner's electric cap lamp.


Corn. A hard rock lining tin lodes. See also: capel.

cap light

a. Dry-cell type. A self-contained light that permits free use of the hands and may be suitable for gaseous or explosive atmospheres. The headlamp, with focusing lens and bulb, is strapped to the head or hat, and the dry cell battery unit can be clipped to the belt. To prevent explosion, the bulb-socket ejects the bulb automatically in case of breakage.

b. Wet-cell type. With rechargeable, wet-cell cap lights, the battery is worn on the belt, and the light unit, which is attached to the cap or head, contains bulbs filled with krypton gas. The head light contains either two separate bulbs or a single bulb with two filaments in parallel, thus assuring the wearer of a constant source of light in the event that one bulb or one filament burns out.

Cappeau furnace

A modification of the Ropp furnace for calcining sulfide ore.

capped fuse

A length of safety fuse to which a blasting cap has been attached.

capped primer

A package or cartridge of cap-sensitive explosive which is specif. designed to transmit detonation to other explosives and which contains a detonator.

capped quartz

A variety of quartz containing thin layers of clay.

cappel; capping

See: capel.


A trigonal mineral, Ba(Y,Ce) (sub 6) Si (sub 3) B (sub 6) O (sub 24) F (sub 2) : weakly radioactive; occurs in veins in syenite associated with wohlerite, rosenbuschite, catapleiite, orangite, lavenite, elaeolite, and sodalite.

cap piece

a. A piece of wood usually 24 to 36 in (60.96 to 91.44 cm) long, 6 to 8 in (15.24 to 20.32 cm) wide, and 2 to 6 in (5.08 to 15.24 cm) thick, that is fitted over a straight post or timber to afford more bearing surface for the support. All single posts, or timbers including safety posts, should be covered with a cap piece to provide additional bearing surface.

b. Arkansas. Usually a piece of wood split from a log.


a. Syn: overburden. Usually used for consolidated material.

b. The overburden or rock deposit overlying a body of mineral or ore. c. See: gossan. d. The preparation of capped fuses. e. The process of sealing or covering a borehole and/or the material or device so used. f. The separation of a block of stone along the bedding plane. g. The attachment at the end of a winding rope. See also: continental gland-type capping; interlocking wedge-type capping; white-metal cappel; capel. h. The fixing of a shackle or a swivel to the end of a hoisting rope. i. The operation of fastening steel rope to a winding cage. j. The name given to a method by which the spouting flow of a liquid or gas from a borehole may be stopped or restricted; also, the mechanism attached to borehole collar piping and so used.

capping station

A special room or building used solely for the preparation of capped fuses.

cap rock

a. Barren vein matter, or a pinch in a vein, supposed to overlie ore. Syn: cap.

b. A hard layer of rock, usually sandstone, a short distance above a coal seam. c. A disklike plate over part of or all of the top of most salt domes in the Gulf Coast States and in Germany. It is composed of anhydrite, gypsum, limestone, and sometimes sulfur. d. A comparatively impervious stratum immediately overlying an oil- or gas-bearing rock. e. Eng. The cap rock of the alum shale, Estuarine sandstones on the Yorkshire coast.


See: capstan.

cap sensitivity

The sensitivity of an explosive to initiation by a detonator. An explosive material is considered to be cap sensitive if it detonates with a No. 8 strength test detonator.

cap set

A term used in square-set mining methods to designate a set of timber using caps as posts, resulting in a set of timber shorter than the normal set.

cap shot

A light shot of explosive placed on the top of a piece of shale that is too large to handle, in order to break it.

cap sill

The upper horizontal beam in the timber framing of a bridge, viaduct, etc.


a. A spoollike drum mounted on a vertical axis used for heave hoisting or pulling. It is operated by steam, electric power, or hand pushes or pulls against bars inserted in sockets provided in the upper flange or head.

b. Sometimes used as a syn. for cathead.

captive mine

Aust. A mine that produces coal or mineral for use by the same company.

captive tonnage

The quantity of mineral product from a mine produced solely for use by the parent company or subsidiary.


In a crystal structure, the substitution of a trace element for a major element of lower valence; e.g., Ba (super +2) for K (super +) . Captured trace elements generally have a higher concentration relative to the major element in the mineral than in the fluid from which it crystallized. CF: admittance; camouflage.