A

Acidic rocks - Igneous rock carrying a high (greater than 65%) proportion of silica.
Adit - An opening driven horizontally into the side of a mountain or hill for providing access to a mineral deposit.
Aeromagnetic survey – An airborne geophysical survey using a magnetometer to measure the earth’s magnetic properties.

Airborne survey - A survey made from an aircraft to obtain photographs, or measure magnetic properties, radioactivity, etc.
Alloy - A compound of two or more metals.
Alluvium - Relatively recent deposits of sedimentary material laid down in river beds, flood plains, lakes, or at the base of mountain slopes. (adj. alluvial)
Alteration - Any physical or chemical change in a rock or mineral subsequent to its formation. Milder and more localized than metamorphism.
Amphibolite - A gneiss or schist largely made up of amphibole and plagioclase minerals.
Anomaly - Any departure from the norm which may indicate the presence of mineralization in the underlying bedrock.
Anthracite - A hard, black coal containing a high percentage of fixed carbon and a low percentage of volatile matter.
Assay - A chemical test performed on a sample of ores or minerals to determine the amount of valuable metals contained.

Autunite – a uranium rich oxide mineral

B

Background - Minor amounts of radioactivity due not to abnormal amounts of radioactive minerals nearby, but to cosmic rays and minor residual radioactivity in the vicinity.
Basalt - An extrusive volcanic rock composed primarily of plagioclase, pyroxene and some olivine.
Basement rocks - The underlying or older rock mass. Often refers to rocks of Precambrian age which may be covered by younger rocks.
Base metal - Any non-precious metal (eg. copper, lead, zinc, nickel, etc.).
Basic rocks - Igneous rocks that are relatively low in silica and composed mostly of dark-coloured minerals.|
Biotite - A platy magnesium-iron mica, common in igneous rocks.
Break - Loosely used to describe a large-scale regional shear zone or structural fault.
Breccia - A rock in which angular fragments are surrounded by a mass of fine-grained minerals.
Bulk sample - A large sample of mineralized rock, frequently hundreds of tonnes, selected in such a manner as to be representative of the potential orebody being sampled. Used to determine metallurgical characteristics.

C

 Calcine - Name given to concentrate that is ready for smelting (i.e. the sulphur has been driven off by oxidation).
Chalcopyrite - A sulphide mineral of copper and iron; the most important ore mineral of copper.
Change house - The mine building where workers change into work clothes; also known as the "dry".
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 deep.
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.
Chromite - The chief ore mineral of chromium.
Cinnabar - A vermilion-coloured ore mineral of mercury.
Clay - A fine-grained material composed of hydrous aluminium silicates.
Cleavage - The tendency of a mineral to split along crystallographic planes.
Coal - A carbonaceous rock mined for use as a fuel.
Complex ore - An ore containing a number of minerals of economic value. The term often implies that there are metallurgical difficulties in liberating and separating the valuable metals.
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 rock formations meet.
Contact metamorphism - Metamorphism of country rocks adjacent to an intrusion, caused by heat from the intrusion.
Continental Crust – the layer of the Earth’s crust that forms the continents and shallow seabed close to their shores.

Core - The long cylindrical piece of rock, about an inch in diameter, brought to surface 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 - Loosely used to describe the general mass of rock adjacent to an orebody. Also known as the host rock.
Crust - The outermost layer of the Earth; includes both continental and oceanic crust.
Cutoff grade - The lowest grade, in percent U3O8, of uranium ore at a minimum specified thickness that can be mined at specified cost.

D

Davidite – a complex mineral consisting of lanthanum, cerium, yttrium and uranium.

Diabase - A common basic igneous rock usually occurring in dykes or sills.
Diamond - The hardest known mineral, composed of pure carbon; low-quality diamonds are used to make bits for diamond drilling in rock.
Diamond drill - A rotary type of rock drill that cuts a core of rock that is recovered in long cylindrical sections, two cm or more in diameter.
Diamond driller - A person who operates a diamond drill.
Diorite - An intrusive igneous rock composed chiefly of sodic plagioclase, hornblende, biotite or pyroxene.
Dip - The angle at which a vein, structure or rock bed is inclined from the horizontal as measured at right angles to the strike.
Disseminated ore - Ore carrying small particles of valuable minerals spread more or less uniformly through the host rock.
Drag fold - The result of the plastic deformation of a rock unit where it has been folded or bent back on itself.
Dump - A pile of broken rock or ore on surface.
Dunnite – an ultramafic rock type

Dyke - A long and relatively thin body of igneous rock that, while in the molten state, intruded a fissure in older rocks. 

E

EM survey - A geophysical survey method which measures the electromagnetic properties of rocks.
En echelon - Roughly parallel but staggered structures.

Environmental impact study - A written report, compiled prior to a production decision, that examines the effects proposed mining activities will have on the natural surroundings.
Epigenetic - Orebodies formed by hydrothermal fluids and gases that were introduced into the host rocks from elsewhere, filling cavities in the host rock.
Epithermal deposit - A mineral deposit consisting of veins and replacement bodies, usually in volcanic or sedimentary rocks, containing precious metals or, more rarely, base metals.
Era - A large division of geologic time - the Precambrian era, for example.
Erosion - The breaking down and subsequent removal of either rock or surface material by wind, rain, wave action, freezing and thawing and other processes.
Exploration - Prospecting, sampling, mapping, diamond drilling and other work involved in searching for ore.

Exploration drilling - Drilling done in search of new mineral deposits, on extensions of known ore deposits, or at the location of a discovery up to the time when the company decides that sufficient ore reserves are present to justify commercial exploitation. Assessment drilling is reported as exploration drilling.

F

Fault - A break in the Earth's crust caused by tectonic forces which have moved the rock on one side with respect to the other.
Feldspar - A group of common rock-forming minerals that includes microcline, orthoclase, plagioclase and others.
Felsic - Term used to describe light-coloured rocks containing feldspar, feldspathoids and silica.
Ferrous - Containing iron.
Fine gold - Fineness is the proportion of pure gold or silver in jewellery or bullion expressed in parts per thousand. Thus, 925 fine gold indicates 925 parts out of 1,000, or 92.5% is pure gold.
Fissure - An extensive crack, break or fracture in rocks.
Float - Pieces of rock that have been broken off and moved from their original location by natural forces such as frost or glacial action.
Fold - Any bending or wrinkling of rock strata.
Footwall - The rock on the underside of a vein or ore structure.
Fracture - A break in the rock, the opening of which allows mineral-bearing solutions to enter. A "cross-fracture" is a minor break extending at more-or-less right angles to the direction of the principal fractures.

G

Gabbro - A dark, coarse-grained igneous rock.
Galena - Lead sulphide, the most common ore mineral of lead.
Gamma - A unit of measurement of magnetic intensity.
Gangue - The worthless minerals in an ore deposit.
Geiger counter - An instrument used to measure the radioactivity that emanates from certain minerals by means of a Geiger-Mueller tube.
Geochemistry - The study of the chemical properties of rocks.
Geology - The science concerned with the study of the rocks which compose the Earth.
Geophysics - The study of the physical properties of rocks and minerals.
Geophysical survey - A scientific method of prospecting that measures the physical properties of rock formations. Common properties investigated include magnetism, specific gravity, electrical conductivity and radioactivity.
Geothermal - Pertains to the heat of the Earth's interior.
Gneiss - A layered or banded crystalline metamorphic rock, the grains of which are aligned or elongated into a roughly parallel arrangement.
Gossan - The rust-coloured capping or staining of a mineral deposit, generally formed by the oxidation or alteration of iron sulphides.
Gouge - Fine, putty-like material composed of ground-up rock found along a fault.
Grab sample - A sample from a rock outcrop that is assayed to determine if valuable elements are contained in the rock. A grab sample is not intended to be representative of the deposit, and usually the best-looking material is selected.
Graben - A down-faulted block of rock.
Granite - A coarse-grained intrusive igneous rock consisting of quartz, feldspar and mica.
Gravity meter, gravimeter - An instrument for measuring the gravitational attraction of the earth; gravitational attraction varies with the density of the rocks in the vicinity.
Greenstone belt - An area underlain by metamorphosed volcanic and sedimentary rocks, usually in a continental shield.
Gypsum - A sedimentary rock consisting of hydrated calcium sulphate.

H

Halite - Rock salt.
Hangingwall - The rock on the upper side of a vein or ore deposit.
Head grade - The average grade of ore fed into a mill.
Heap leaching - A process whereby valuable metals are leached from a heap, or pad, of crushed ore by leaching solutions percolating down through the heap and collected from a sloping, impermeable liner below the pad.

Hematite - An oxide of iron, and one of that metal's most common ore minerals.
High grade - Rich ore. As a verb, it refers to selective mining of the best ore in a deposit.
Hornfels - A fine-grained contact metamorphic rock.
Horst - An up-faulted block of rock.
Host rock - The rock surrounding an ore deposit.
Hydrometallurgy - The treatment of ore by wet processes, such as leaching, resulting in the solution of a metal and its subsequent recovery.
Hydrothermal - Relating to hot fluids circulating in the earth's crust. 

I

Igneous rocks - Rocks formed by the solidification of molten material from far below the earth's surface.
Ilmenite - An ore mineral of titanium, being an iron-titanium oxide.
Induced polarization - A method of ground geophysical surveying employing an electrical current to determine indications of mineralization.
Industrial minerals - Non-metallic, non-fuel minerals used in the chemical and manufacturing industries. Examples are asbestos, gypsum, salt, graphite, mica, gravel, building stone and talc.

In Situ – meaning in its original place or location.

In Situ Leach mining (ISL) - The recovery, by chemical leaching, of the valuable components of an orebody without physical extraction of the ore from the ground. Also referred to as “solution mining.”
Intermediate rock - An igneous rock containing 52% to 66% quartz.
Intrusive - A body of igneous rock formed by the consolidation of magma intruded into other rocks, in contrast to lavas, which are extruded upon the surface.

J

 

JORC - An acronym for Joint Ore Reserve Committee.  The Code has been adopted by the Australasian Institute of Mining and Metallurgy (AusIMM) and the Australian Institute of Geoscientists (AIG), and is binding on their respective members.  It is endorsed by the Minerals Council of Australia and the Securities Institute of Australia.  The Code has been adopted by and included in the listing rules of the Australian (ASX) and New Zealand (NZX) Stock Exchanges, the purpose of which is to set the regulatory enforceable standards or a Code of Practice for the reporting of Mineral Resources and Ore Reserves.

K

Kimberlite - A variety of peridotite; the most common host rock of diamonds.

Komatiite – a high magnesium oxide ultramafic rock, often with olivine Spinifex textures

L

Lamprophyre - An igneous rock, composed of dark minerals, that occurs in dykes; sometimes contains diamonds.
Laterite - A residual soil, usually found in tropical countries, out of which the silica has been leached. May form orebodies of iron, nickel, bauxite and manganese.
Lava - A general name for the molten rock ejected by volcanoes.
Leachable - Extractable by chemical solvents.
Leaching - A chemical process for the extraction of valuable minerals from ore; also, a natural process by which ground waters dissolve minerals, thus leaving the rock with a smaller proportion of some of the minerals than it contained originally.
Lens - Generally used to describe a body of ore that is thick in the middle and tapers towards the ends.
Lenticular - A deposit having roughly the form of a double convex lens.
Limestone - A bedded, sedimentary deposit consisting chiefly of calcium carbonate.
Limonite - A brown, hydrous iron oxide.
Logging - The process of recording geological observations of drill core either on paper or on computer disk.
London Metals Exchange - A major bidding market for base metals, which operates daily in London.

M

Mafic - Igneous rocks composed mostly of dark, iron- and magnesium-rich minerals.
Magma - The molten material deep in the Earth from which rocks are formed.
Magnetic gradient survey - A geophysical survey using a pair of magnetometers a fixed distance apart, to measure the difference in the magnetic field with height above the ground.
Magnetic susceptibility - A measure of the degree to which a rock is attracted to a magnet.
Magnetite - Black, magnetic iron ore, an iron oxide.
Magnetometer - An instrument used to measure the magnetic attraction of underlying rocks.
Marble - A metamorphic rock derived from the recrystallisation of limestone under intense heat and pressure.
Marginal deposit - An orebody of minimal profitability.
Metallurgical coal - Coal used to make steel.
Metallurgy - The study of extracting metals from their ores.
Metamorphic rocks - Rocks which have undergone a change in texture or composition as the result of heat and/or pressure.
Metamorphism - The process by which the form or structure of rocks is changed by heat and pressure.
Migmatite - Rock consisting of thin, alternating layers of granite and schist.
Minable reserves - Ore reserves that are known to be extractable using a given mining plan.
Mineral - A naturally occurring homogeneous substance having definite physical properties and chemical composition and, if formed under favourable conditions, a definite crystal form.

N

Native metal - A metal occurring in nature in pure form, uncombined with other elements.
Net smelter return - A share of the net revenues generated from the sale of metal produced by a mine.
Norite - A coarse-grained igneous rock that is host to copper/nickel deposits in the Sudbury area of Ontario.
Nugget - A small mass of precious metal, found free in nature. 

O

Oceanic crust – the layer of the Earth’s crust that forms the oceanic basins and is primarily composed of mafic rocks.

Olivine – a magnesium iron silicate mineral

Open pit - A mine that is entirely on surface. Also referred to as open-cut or open-cast mine.
Ophiolite – a section of the Earth’s oceanic crust and mantle that has been uplifted and exposed on continental crustal rocks.

Ore - A mixture of ore minerals and gangue from which at least one of the metals can be extracted at a profit.
Orebody - A natural concentration of valuable material that can be extracted and sold at a profit.
Ore Reserves - The calculated tonnage and grade of mineralization which can be extracted profitably; classified as possible, probable and proven according to the level of confidence that can be placed in the data.
Orogeny - A period of mountain-building characterized by the folding of a portion of the earth's crust.
Outcrop - An exposure of rock or mineral deposit that can be seen on surface, that is, not covered by soil or water.
Overturned - Where the oldest sedimentary rock beds are lying on top of a younger beds.
Oxidation - A chemical reaction caused by exposure to oxygen that results in a change in the chemical composition of a mineral. 

P

Paleodrainage – ancient drainage systems

Pegmatite - A coarse-grained, igneous rock, generally coarse, but irregular in texture, and similar to a granite in composition; usually occurs in dykes or veins and sometimes contains valuable minerals.
Pentlandite - Nickel iron sulphide, the most common nickel ore.
Peridotite - An intrusive igneous rock consisting mainly of olivine.
Phaneritic - A term used to describe the coarse-grained texture of some igneous rocks.
Phosphate – salt of phosphoric acid, rich in phosphor

Pig iron - Crude iron from a blast furnace.
Pitchblende - An important uranium ore mineral. It is black in colour, possesses a characteristic greasy lustre and is highly radioactive.
Placer - A deposit of sand and gravel containing valuable metals such as gold, tin or diamonds.
Plant - A building or group of buildings in which a process or function is carried out; at a mine site it will include warehouses, hoisting equipment, compressors, maintenance shops, offices and the mill or concentrator.
Plate tectonics - A geological theory which postulates that the Earth's crust is made up of a number of rigid plates which collide, rub up against and spread out from one another.
Plug - A common name for a small offshoot from a large body of molten rock.
Plunge - The vertical angle a linear geological feature makes with the horizontal plane.
Plutonic - Refers to rocks of igneous origin that have come from great depth.
Porphyry - Any igneous rock in which relatively large crystals, called phenocrysts, are set in a fine-grained groundmass.
Possible reserves - Valuable mineralization not sampled enough to accurately estimate its tonnage and grade, or even verify its existence. Also called "inferred reserves."
Potash - Potassium compounds mined for fertilizer and for use in the chemical industry.
Primary deposits - Valuable minerals deposited during the original period or periods of mineralization, as opposed to those deposited as a result of alteration or weathering.
Probable reserves - Valuable mineralization not sampled enough to accurately estimate the terms of tonnage and grade. Also called "indicated reserves."
Prospect - A mining property, the value of which has not been determined by exploration.
Proven reserves - Reserves that have been sampled extensively by closely spaced diamond drill holes and developed by underground workings in sufficient detail to render an accurate estimation of grade and tonnage. Also called "measured reserves."
Pulp - Pulverized or ground ore in solution.
Pyrite - A yellow iron sulphide mineral, normally of little value. It is sometimes referred to as "fool's gold".
Pyrrhotite - A bronze-coloured, magnetic iron sulphide mineral. 

Q

Quartz - Common rock-forming mineral consisting of silicon and oxygen.
Quartzite - A metamorphic rock formed by the transformation of a sandstone by heat and pressure.

R

 

Radioactivity - The property of spontaneously emitting alpha, beta or gamma rays by the decay of the nuclei of atoms.

Radiometric Survey – Generally an airborne survey measuring the radioactivity of the earth’s surface.
Radon survey - A geochemical survey technique which detects traces of radon gas, a product of radioactivity.
Rare earth elements - Relatively scarce minerals such as niobium and yttrium.
Reconnaissance - A preliminary survey of ground.
Recovery - The percentage of valuable metal in the ore that is recovered by metallurgical treatment.
RedOx – the boundary between reducing and oxidising conditions

Refractory ore - Ore that resists the action of chemical reagents in the normal treatment processes and which may require pressure leaching or other means to effect the full recovery of the valuable minerals.
Regional metamorphism - Metamorphism caused by both the heat of igneous processes and tectonic pressure.
Resource - The calculated amount of material in a mineral deposit, based on limited drill information.
Rhyolite - A fine-grained, extrusive igneous rock which has the same chemical composition as granite.
Rock - Any natural combination of minerals; part of the earth's crust.

Roll front - A type of uranium deposition localised as a roll or interface separating an oxidized interior from a reduced exterior. The reduced side of this interface is significantly enriched in uranium.
Rotary drill - A machine that drills holes by rotating a rigid, tubular string of drill rods to which is attached a bit. Commonly used for drilling large-diameter blast holes in open-pit mines.
Royalty - An amount of money paid at regular intervals by the lessee or operator of an exploration or mining property to the owner of the ground. Generally based on a certain amount per tonne or a percentage of the total production or profits. Also, the fee paid for the right to use a patented process.

S

Sample - A small portion of rock or a mineral deposit taken so that the metal content can be determined by assaying.
Sampling - Selecting a fractional but representative part of a mineral deposit for analysis.
Sandstone - A sedimentary rock consisting of grains of sand cemented together.
Saprolite – chemically weathered rock

Scarp - An escarpment, cliff or steep slope along the margin of a plateau, mesa or terrace.
Schist - 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.
Scoping Study – preliminary evaluation of the economic parameters of a potential mining operation.

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.
Sedimentary rocks - Secondary rocks formed from material derived from other rocks and laid down under water. Examples are limestone, shale and sandstone.
SEDEX – Sedimentary Exhalative deposits, generally referring to base metal deposits.

Serpentine - A greenish, metamorphic mineral consisting of magnesium silicate.
Shale - 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.
Siderite - 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.
Silica - Silicon dioxide. Quartz is a common example.
Siliceous - A rock containing an abundance of quartz.
Sill - An intrusive sheet of igneous rock of roughly uniform thickness that has been forced between the bedding planes of existing rock.
Silt - Muddy deposits of fine sediment usually found on the bottoms of lakes.
Skarn - Name for the metamorphic rocks surrounding an igneous intrusive where it comes in contact with a limestone or dolostone formation.
Slate - A metamorphic rock; the metamorphic equivalent of shale.
Slickenside - The striated, polished surface of a fault caused by one wall rubbing against the other.
Sphalerite - A zinc sulphide mineral; the most common ore mineral of zinc.
Step-out drilling - Holes drilled to intersect a mineralization horizon or structure along strike or down dip.
Stockpile - Broken ore heaped on surface, pending treatment or shipment.
Stratigraphy - Strictly, the description of bedded rock sequences; used loosely, the sequence of bedded rocks in a particular area.
Strike - The direction, or bearing from true north, of a vein or rock formation measure on a horizontal surface.
Stringer - A narrow vein or irregular filament of a mineral or minerals traversing a rock mass.
Sulphide - A compound of sulphur and some other element.
Syenite - An intrusive igneous rock composed chiefly of orthoclase.
Sylvite - potassium chloride, the principal ore of potassium mined for fertilizer manufacturing.
Syncline - A down-arching fold in bedded rocks.
Syngenetic - 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.)

T 

Talus - A heap of broken, coarse rock found at the base of a cliff or mountain.
Telluride - A chemical compound consisting of the element tellurium and another element, often gold or silver.
Tenure – having recognised rights or a licence over an area.

Tertiary – the geological time span between 65 million and 1.8 million years ago.

Thermal coal - Coal burned to generate the steam that drives turbines to generate electricity.
Trench - A long, narrow excavation dug through overburden, or blasted out of rock, to expose a vein or ore structure.
Trend - The direction, in the horizontal plane, of a linear geological feature, such as an ore zone, measured from true north.
Tuff - Rock composed of fine volcanic ash.

U

U₃O₈ – Uranium oxide

Ultramafic – igneous rocks containing very low levels of silica

Umpire sample or assay - An assay made by a third party to provide a basis for settling disputes between buyers and sellers of ore.
Unconformity – a buried erosion surface separating two rock units of different ages

Uncut value - The actual assay value of a core sample as opposed to a cut value which has been reduced by some arbitrary formula.

Uraninite - A uranium mineral with a high uranium oxide content. Frequently found in pegmatite dykes.
Uranium - A heavy, naturally radioactive, metallic element (atomic number 92). Its two principally occurring isotopes are 235U and 238U. The isotope 235U is indispensable to the nuclear industry because it is the only isotope existing in nature to any appreciable extent that is fissionable by thermal neutrons. The isotope 238U is also important because it absorbs neutrons to produce a radioactive isotope that subsequently decays to the isotope 239Pu, which also is fissionable by thermal neutrons.
Uranium deposit - A discrete concentration of uranium mineralization that is of possible economic interest.
Uranium ore - Rock containing uranium mineralization in concentrations that can be mined economically, (typically 1 to 4 pounds of U3O8 per ton or 0.05 to 0.20 percent U3O8).
Uranium oxide - Uranium concentrate or yellowcake. Abbreviated as U3O8.
Uranium reserves - Estimated quantities of uranium in known mineral deposits of such size, grade, and configuration that the uranium could be recovered at or below a specified production cost with currently proven mining and processing technology and under current law and regulations. Reserves are based on direct radiometric and chemical measurements of drill hole and other types of sampling of the deposits. Mineral grades and thickness, spatial relationships, depths below the surface, mining and reclamation methods, distances to milling facilities, and amenability of ores to processing are considered in the evaluation. The amounts of uranium in ore that could be exploited within the chosen forward-cost levels are estimated utilizing available sampling, engineering, geologic, and economic data in accordance with conventional engineering practices.
Uranium resources categories - Three categories of uranium resources are used to reflect differing levels of confidence in the resources reported. Reasonably assured resources (RAR), estimated additional resources (EAR), and speculative resources (SR) are described below....
                       Reasonably assured resources (RAR) - The uranium that occurs in known mineral deposits of such size, grade, and configuration that it could be recovered within the given production cost ranges, with currently proven mining and processing technology. Estimates of tonnage and grade are based on specific sample data and measurements of the deposits and on knowledge of deposit characteristics. RAR correspond to DOE's uranium reserves category.
                       Estimated additional resources (EAR) - The uranium in addition to RAR that is expected to occur, mostly on the basis of direct geological evidence, in extensions of well-explored deposits, little explored deposits, and undiscovered deposits believed to exist along well-defined geological trends with known deposits, such that the uranium can subsequently be recovered within the given cost ranges. Estimates of tonnage and grade are based on available sampling data and on knowledge of the deposit characteristics, as determined in the best-known parts of the deposit or in similar deposits. EAR correspond to DOE's probable potential resources category.
                       Speculative resources (SR) - Uranium in addition to EAR that is thought to exist, mostly on the basis of indirect evidence and geological extrapolations, in deposits discoverable with existing exploration techniques. The locations of deposits in this category can generally be specified only as being somewhere within given regions or geological trends. The estimates in this category are less reliable than estimates of RAR and EAR. The category of SR corresponds to DOE's possible potential resources plus speculative potential resources categories combined.

V

Vein - A fissure, fault or crack in a rock filled by minerals that have travelled upwards from some deep source.
Visible gold - Native gold which is discernible, in a hand specimen, to the unaided eye.
Volcanic rocks - Igneous rocks formed from magma that has flowed out or has been violently ejected from a volcano.
Volcanogenic - A term used to describe the volcanic origin of mineralization.
Voting right - The stockholder's right to vote in the affairs of the company.

VTEM – Versatile Time-Domain Electromagnetic survey, used to detect conductive substances at shallow depths in the Earth’s crust.

Vug - A small cavity in a rock, frequently lined with well-formed crystals. Amethyst commonly forms in these cavities.

Xenolith - A fragment of country rock enclosed in an intrusive rock.

Y

Yellowcake - A natural uranium concentrate that takes its name from its colour and texture. Yellowcake typically contains 70 to 90 percent U3O8 by weight. It is used as feedstock for uranium fuel enrichment and fuel pellet fabrication. Yellow cake is also known as "uranium oxide" (see uranium oxide).

Z

Zone - An area of distinct mineralization.
Zone of oxidation - The upper portion of an orebody that has been oxidized.