Formation shaped like a saddle or anticline.


The act of introducing metals or minerals into a deposit or samples, resulting in false assays - done either by accident or with the intent of defrauding the public.


A small portion of rock or a mineral deposit, taken so that the metal content can be determined by assaying.


Selecting a fractional but representative part of a mineral deposit for analysis.


A sedimentary rock consisting of grains of sand cemented together.


The act of removing loose slabs of rock from the back and walls of an underground opening, usually done with a hand-held scaling bar or with a boom-mounted scaling hammer.


An escarpment, cliff or steep slope along the margin of a plateau, mesa or terrace.


A foliated metamorphic rock the grains of which have a roughly parallel arrangement; generally developed by shearing.

Scintillation counter: 

An instrument used to detect and measure radioactivity by detecting gamma rays; more sensitive than a Geiger counter.


Self-contained underwater breathing apparatus.


A unit of water flow measure equal to one cubic foot per second, or 448.83 gallons per minute.


An alteration of an original formation or deposit.

Secondary enrichment: 

Enrichment of a vein or mineral deposit by minerals that have been taken into solution from one part of the vein or adjacent rocks and redeposited in another.


Formed by the deposition of eroded material. Pertaining to sediments laid down by rivers and streams.

Sedimentary rocks: 

Secondary rocks formed from material derived from other rocks and laid down under water. Examples are lime stone, shale and sandstone.

Seismic prospecting: 

A geophysical method of prospecting, utilizing knowledge of the speed of reflected sound waves in rock.


A technique, used in geophysical prospecting, which recognizes and measures the minute electric currents generated by sulfide deposits.

Semi-autogenous grinding (SAG): 

A method of grinding rock into fine powder whereby the grinding media consist of larger chunks of rocks and steel balls.

Semi-autogenous mill: 

A mill in which rock is reduced to smaller particles partially by grinding against other pieces of rock.


A greenish, metamorphic mineral consisting of magnesium silicate.


The main support timbers in a mine tunnel.


A vertical or inclined passageway in an underground mine for moving personnel, equipment, supplies and material including ore and waste rock for the purpose of providing access to an orebody. Usually equipped with a hoist at the top, which lowers and raises a conveyance.

Shaker table: 

A large table with groves on a slight incline which is vibrated so that ore concentrates places at the top end will classify and separate the gold from the waste materials.


Sedimentary rock formed by the consolidation of mud or silt.

Shear or shearing: 

The deformation of rocks by lateral movement along innumerable parallel planes, generally resulting from pressure and producing such metamorphic structures as cleavage and schistosity.

Shear zone: 

A zone in which shearing has occurred on a large scale.

Sheave wheel: 

A large grooved wheel in the top of a headframe over which the hoisting rope passes. (a pulley)


A concentration of mineral values; that part of a vein or zone carrying values of ore grade.

Short ton: 

2,000 lb avoirdupois.

Shrinkage stoping: 

A stoping method which uses part of the broken ore as a working platform and as support for the walls of the stope.


Iron carbonate, which when pure, contains 48.2% iron; must be roasted to drive off carbon dioxide before it can be used in a blast furnace. (Roasted product is called sinter).


An oxide of silicon. (Quartz is a common example.)


A rock containing an abundance of quartz.


An intrusive sheet of igneous rock of roughly uniform thickness, generally extending over considerable lateral extent, that has been forced between the bedding planes of existing rock.


Muddy deposits of fine sediment usually found on the bottoms of lakes.

Single jack: 

A light hammer used for drilling holes by hand.


To descend on a vein.


Fine particles of iron ore that have been treated by heat to produce blast furnace feed.


A term used to describe the metamorphic rocks surrounding an igneous intrusive where the latter comes in contact with a limestone or dolomite rock formation.


A self-dumping bucket used in a shaft for hoisting ore or rock.


A superficial, thin layer of gold-bearing sand and gravel that accumulated on the surface of river gravel deposits.


The vitreous mass separated from the fused metals in the smelting process.


The process of blasting rock from the side of an underground opening to widen the opening.


A metamorphic rock; the metamorphic equivalent of shale.

Slick sheet: 

A sheet of wood or metal which is placed on the ground at the face so the muck can be knocked down onto it. This provides a smooth surface for sliding shovels on when shoveling the muck into wheelbarrows or ore cars.


The striated, polished surface of a fault caused by one wall rubbing against the other.


Refers to displacement along a fault.


An inclined entry to underground workings.


Rock cuttings from a diamond drill hole, sometimes used for assaying.

Sluice Box: 

A container which utilizes gravity to recover gold and other heavy minerals from gravels washed through it by flowing water.

Slush bucket: 

A device which is used to move muck away from an underground work area. It is sort of plow blade mounted on a frame which is attached to a double drum winch for dragging in and out of the muck area. It slides backwards onto the muck pile when winched in, and is then drug back out by the winch as the blade digs into the pile grabbing the muck and pulling in out with it.


A metallurgical operation performed in a furnace where metal is separated from impurities by a process that includes fusion.

Smelter (Refinery): 

A facility which processes ore or metal concentrate (such as copper or zinc) produced by a mine into a high grade product which is then normally further treated in a refinery to produce essentially pure metal.

Sodium cyanide: 

A chemical used in the mill of gold ores to dissolve gold and silver.

Solvent extraction-Electrowinning (SX-EW): 

A metallurgical technique, so far applied only to copper ores. The process which takes copper-bearing aqueous solutions (usually generated by leaching of piles or "heaps" of copper-bearing ore), purifies the solution by removing metals other than copper from the solution through the use of organic solvents, and then electroplates 99.99% pure copper plates ("cathodes") for sale to customers. The process bypasses conventional smelting and is used at Quebrada Blanca.

Spark arrestor: 

A metal container on gasoline engines to prevent sparks from leaving the exhaust and possibly starting a fire.

Specific gravity: 

The relative weight of a mineral as compared to the weight of an equal volume of water, also referred to as density.


A selected piece of rock or ore taken for examination or display.


The zinc of commerce, more or less impure, cast from molten metal into slabs or ingots.


A sulfide mineral of zinc; a common ore mineral of zinc.

Spill-Containment Berm: 

An earthen structure built to contain possible spills and effluent discharge.


Rods or pipes which are driven into the top of the face in the direction the tunnel is going. These help to support the ceiling as material is removed in preparation for placing the next set.


The action of using spile in loose ground while advancing in a tunnel.

Spiral concentrator: 

A revolving drum or pan with an interior section made of spiral riffles, used for gravity concentration of heavy minerals.

Spot price: 

Current delivery price of a commodity traded in the spot market, also called the cash price.

Stamp mill: 

A ore processing plant which uses a device which has heavy steel weights that repeatedly drop onto steel anvils which the ore is fed between.


An enlargement of a shaft made for the storage and handling of equipment and for driving drifts at that elevation.

Step-out drilling: 

Holes drilled to intersect a mineralization horizon or structure along strike or down dip.


Broken ore heaped on surface, pending treatment or shipment.


An excavation in a mine from which ore is being or has been extracted.


A formation having banded layers, or beds.


Pertaining to the composition, sequence and correlation of stratified rocks.


Strictly, the description of bedded rock sequences; used loosely, the sequence of bedded rocks in a particular area.


A physical characteristic of minerals determined by scratching a sample of the mineral on a piece of unglazed porcelain.


Prominent scratches left on bedrock by advancing glaciers.


The direction, course, or bearing, from true north of a vein or rock formation measured on a level horizontal surface.


A narrow vein or irregular filament of mineral traversing a rock mass.


To remove the overburden or waste rock overlying an orebody in preparation for mining by open pit methods.

Stripping ratio: 

The ratio of tonnes removed as waste relative to the number of tonnes of ore removed from an open pit mine.

Strip mine: 

An open pit mine, usually a coal mine, mined by removing overburden, excavating the coal seam, then returning the overburden.


The general form and type of rock formation.


A black coal, intermediate between lignite and bituminous.


A level or working horizon in a mine between main working levels.

Suction dredge: 

A device which acts like an underwater vacuum cleaner for the purpose of sucking up materials for gold processing.


A compound of sulfur and some other element. Example: iron sulfide.

Sulfide dust explosions: 

An underground mining hazard involving the spontaneous combustion of airborne dust containing sulfide minerals.

Sulfide ore: 

A sub-group of refractory ore-mineralized rock in which much of the gold is encapsulated in sulfides and is not readily amenable to dissolution by cyanide solutions, associated with sulfide minerals (primarily pyrite) that have not been oxidized. Some sulfide ore may require autoclave treatment prior to milling.

Sulfur dioxide: 

A gas liberated during the smelting of most sulfide ores; either converted into sulfuric acid or released into the atmosphere in the form or a gas.


An underground excavation where water accumulates before being pumped to surface.

Surf washer: 

A small sluice that is placed so that the incoming surf can run up and down the trough, washing material from a hopper down over riffles.

Sustainable development: 

Industrial development that does not detract from the potential of the natural environment to provide benefits to future generations.


A term used for changing the corners of a mining claim to agree with the strike of the vein if it turns out to be different than originally believed when the claim was filed.


An intrusive igneous rock composed chiefly of orthoclase.


The principal ore of potassium.


A down-arching fold in bedded rocks.


A term used to describe when mineralization in a deposit was formed relative to the host rocks in which it is found. In this case, the mineralization was formed at the same time as the host rocks. (The opposite is epigenetic).