| Cable bolt: | A steel cable, capable of withstanding tens of tonnes, cemented into a drillhole to lend support in blocky ground. |
| Cache: | A place where supplies are stored or hidden. |
| Cage: | The conveyance used to transport men and equipment in a shaft. |
| Caisson: | A metal casing or cylinder used to sink shafts in unstable or wet placer ground. |
| Calcareous: | Like limestone or calcium carbonate, or composed of same. |
| Calcine: | Name given to concentrate that is ready for smelting (i.e. the sulfur has been driven off by oxidation). |
| Caldera: | A volcanic center which has collapsed and left a ring shaped feature. |
| Caliche: | The common name for the hardened layers of mostly calcium salts, chlorides, carbonates and sulfates which cement together the material. In some parts of the world it is known as "calcrete" where the name describes its rock-hard nature. |
| Calorie: | Heat required to raise the temperature of 1 gram of water by 1 degree Centigrade. |
| Cam: | Projection on a shaft that impart irregular motion or reciprocating action to another part; also the shaft itself. |
| Cap rock: | A layer of rock lying on top of another type of rock. |
| Capillarity: | The property of liquids allowing them to rise through solids. |
| Captive stope: | A stope that is accessible only through a manway. |
| Carat: | Unit of weight used for precious stones, equal to 3.2 grains. |
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Carbon steel: |
A steel hardened by the addition of carbon; drill rod. |
| Carbonaceous: | Refers to rocks containing carbon. |
| Carboniferous: | A geological time period. |
| Carbon-in-leach: | A process very similar to carbon-in-pulp, but the leaching and absorbing of gold onto carbon take place in the same tank. In this recovery process a slurry of gold ore free carbon granules and cyanide are mixed together. The cyanide dissolves the gold content and the gold is absorbed on the carbon; the carbon is then separated from the slurry for further gold removal. |
| Carbon-in-pulp: | A process to recover gold from a cyanide leach slurry. Coarse, activated carbon particles (typically ground up coconut shells) are moved counter-current to the slurry, absorbing the gold. Loaded carbon is removed by screening, and the gold is recovered from the carbon by stripping in a caustic cyanide solution followed by electrolysis or by zinc precipitation. |
| Carborundum: | A trademarked name for an abrasive made of silicon carbide crystals. |
| Casing head: | Hardened fitting on top of casing, used for driving casing. |
| Cathode: | A rectangular plate of metal, produced by electrolytic refining, which is melted into commercial shapes such as wirebars, billets, ingots, etc. |
| Cathode Copper: | The product from a copper refinery or Solvent Extraction-Electrowinning (SX-EW) process. |
| Caustic: | Corrosive chemical substance. |
| Cave In: | Collapse of mine workings. |
| Caving: | A mining method where ore is purposely caved. |
| Cement copper: | Copper that has been salvaged from its solution in groundwater or mine drainage water by precipitating on scrap iron, a process commonly used in the U.S. |
| Centigrade: | A system for measuring temperature. |
| Ceramic: | Refers to clays hardened by roasting. |
| Cesium Magnetometer: | An instrument used in geophysics which measures magnetic field strength in terms of vertical gradient and total field. |
| Chain: | Survey measure equal to 66 feet. |
| Chalcocite: | A sulfide mineral of copper common in the zone of secondary enrichment. |
| Chalcopyrite: | A sulfide mineral of copper and iron. A common ore mineral of copper. |
| Change house: | A special building, constructed at a mine site, where the miner changes into work clothes; also known as the "dry". |
| Channel: | The main section of a watercourse. |
| Channel sample: | A sample composed of pieces of vein or mineral deposit that have been cut out of a small trench or channel, usually about 10 cm wide and 2 cm or so deep. |
| Check valve: | Device for controlling flow of liquids or gasses. |
| Chemical analysis: | Determination of content by chemistry. |
| Chemical: | Refers to substances involved in reaction between the elements. |
| Chip sample: | A method of sampling a rock exposure whereby a regular series of small chips of rock is broken off along a line across the face. |
| Chlorination: | The process where a sample is subjected to acids and chlorine which solubilize precious metals. The resulting 'pregnant' liquor is then analyzed via AA or ICP. The precious metals are stripped from the pregnant liquor to physically recover the metals. |
| Chromite: | A black to brownish-black chromium ore which is rich in the chrome. Often used as a geochemical indicator of platinum group elements. |
| Chromium: | A gray metallic element found in the mineral chromite. |
| Chute: | An opening, usually constructed of timber and equipped with a gate, through which ore is drawn from a stope into mine cars. |
| Cinnabar: | A vermilion-colored ore mineral of mercury. |
| Circulating load: | Over-sized chunks of ore returned to the head of a closed grinding circuit before going on to the next stage of treatment. |
| Claim: | A portion of land held either by a prospector or a mining company under federal or provincial law. The common size is 1,320 ft. (about 400 m) square, containing 40 acres (about 16 ha). |
| Clarification: | Process of clearing dirty water by removing suspended material. |
| Classifier: | A mineral-processing machine which separates minerals according to size and density. |
| Clastic rock: | A sedimentary rock composed principally of fragments derived from pre-existing rocks and transported mechanically to their place of deposition. |
| Clay: | A fine-grained material composed of hydrous aluminum silicates. |
| Cleavage: | A property of many minerals which may be easily split along crystallographic planes. |
| Closed circuit: | A loop in the milling process wherein a selected portion of the product of a machine is returned to the head of the machine for finishing to required specification; commonly used examples in milling plants include grinding mills in closed circuit with classifiers. |
| Coal: | A combustible carbonaceous rock. |
| Coalification: | The metamorphic processes of forming coal. |
| Coarse gold: | General term applied to rough or angular gold particles as well as to larger pieces or nuggets. |
| Cobbles: | Rock fragments between 64 and 256 millimeters in diameter, especially one that has been naturally rounded. In dredging, these are the rocks that are too big to get sucked through the nozel yet still small enough to get thrown aside by hand. |
| Collar: | The term applied to the timbering or concrete around the mouth of a shaft; also used to describe the top of a mill hole. |
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Collectors, 'Buttons':
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Metals whose physical properties make precious metals soluble and collect into a solid button when smelted. Lead, mercury, copper and nickel are collectors commonly used in metallurgical techniques. |
| Colloidal gold: | Extremely fine gold particles that can remain suspended in solution. |
| Color: | The term given very small particles of visible gold. |
| Column flotation: | A milling process, carried out in a tall cylindrical column, whereby valuable minerals are separated from gangue minerals based on their wetability properties. |
| Common-core training: | Underground hardrock mining skills taught to all underground miners. |
| Complex ore: | An ore containing a number of minerals of economic value. Usually implies there are metallurgical difficulty in liberating and separating the valuable metals. |
| Compressor: | A machine for compressing air to a pressure sufficient to actuate mine machinery. |
| Cone crusher: | A machine which crushes ore between a gyrating cone or crushing head and an inverted truncated cone known as a bowl. |
| Concentrate: | A fine, powdery product of the milling process containing valuable metal and from which most of the waste material in the ore has been eliminated and discarded as tailings. |
| Concentrator: | A facility in which the mineral content of ore produced from a mine is upgraded to a product containing a higher percentage of metal in a "concentrate", which is then shipped to a smelter and/or refinery, a milling plant that produces a concentrate of the valuable minerals or metals. Further treatment is required to recover the pure metal. |
| Confined aquifer: | An aquifer (or water bearing zone) where the pressure (or generically the water) level is above the top of the aquifer. |
| Conglomerate: | A sedimentary rock consisting of rounded, water-worn pebbles or boulders cemented into a solid mass. |
| Contact: | A geological term used to describe the line or plane along which two different rocks come together. |
| Contact metamorphism: | Metamorphism of country rocks adjacent to an intrusion, caused by heat from the intrusion. |
| Contained ounces: | This is ounces in the ground without considering a reduction for ounces not recoverable by the applicable mining process. |
| Contiguous: | Sharing an edge or boundary; connecting without a break. |
| Continental crust: | The thick, solid part of the Earth's crust underlying the continents. |
| Continental drilling: | Deep drilling projects up to 5 km deep, conducted by scientific research institutions worldwide to learn more about the deep structure of the continental crust. |
| Continuous miner: | A piece of mining equipment which produces a continuous flow of ore from the working face. |
| Controlled blasting: | Blasting patterns and sequences designed to achieve a particular objective. Cast blasting, where the muck pile is cast in a particular direction, and deck blasting, where holes are loaded once but blasted in successive blasts days apart, are examples. |
| Converter: | In copper smelting, a Bessemer furnace is used to separate copper metal from matte; also used in steel making. |
| Cordillera: | The continuous chain of mountain ranges on the western margin of North and South America.. |
| Cordilleran Region: | The continuous chain or range of mountains on the western margin of North America. |
| Core: | The long cylindrical piece of rock, about 2 cm or more in diameter, recovered by diamond drilling. |
| Core barrel: | That part of a string of tools in a diamond drill hole in which the core specimen is collected. |
| Country rock: | A loose term to describe the general mass of rock adjacent to an orebody, as distinguished from the vein or ore deposit itself. Also known as the host rock. |
| Cousin Jack: | A male miner from Cornwall England which often would try to get a job for another miner from his home town by asking the boss if he had a job for his “cousin Jack”. |
| Cousin Jenny: | The female partner of a Cousin Jack and of the same heritage. |
| Cradle: | Refers to a gold rocker. |
| Crevices: | Cracks and breaks, usually in bedrock. |
| Crevicing: | The cleaning of cracks and crevices in the bedrock beneath a watercourse for the gold particles lodged therein. Also called "sniping". |
| Cribbing : | Timbering used to support shafts in wet or loose gravels. |
| Crosscut: | A horizontal opening driven from a shaft and at right angles to the strike of a vein or rock formation. |
| Crusher: | A machine for crushing rock, such as a gyratory crusher, jaw crusher or cone crusher. |
| Crust: | The upper surface of the earth. |
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Crystals: |
Formations of minerals that helps determine their contents. |
| Custom smelter: | A smelter which processes concentrates from independent mines. Concentrates may be purchased or the smelter may be contracted to do the processing for the independent company. |
| Cut-and-fill: | A method of stoping in which ore is removed in slices, or lifts, following which the excavation is filled with rock or other waste material known as backfill, before the subsequent slice is mined; the backfill sup- ports the walls of the stope. |
| Cut-off grade: | The lowest grade of mineralized material considered economic; used in the calculation of the ore reserves in a given deposit. |
| Cut value: | Applies to assays that have been reduced to some arbitrary maximum - thus high erratic values are reduced in order not to have an undue influence on the overall average. |
| Cyanidation: | A method of extracting exposed gold or silver grains from crushed or ground ore by dissolving it in a weak solution of sodium- or calcium-cyanide. Also known as leaching. May be carried out in tanks inside a mill or in heaps of ore out of doors. |
| Cyanidation: | A method of extracting gold grains from crushed or ground ore by dissolving them in a weak solution of sodium or calcium cyanide: also known as Cyanide leaching. |
| Cyanide: | A highly toxic chemical compound used to dissolve gold and silver from ore. |