Minerals - Glossary

Vanadates (group)
It is a name given to that group of minerals which are compounds of one or more metallic element associated with the vanadate radical (VO₄). The vanadates along with the related arsenates are classified in the phosphate group. Vanadates are mostly heavy, generally brittle but they are not hard. They occur in small crystals or compact aggregates.

Variable formula
It is a chemical formula of a mineral which includes all common elemental replacements, like adamite, Zn₂(AsO₄)(OH), most of the time contains part of the zinc (Zn) replaced by copper (Cu) or cobalt (Co). Then the variable formula is (Zn,Cu,Co)₂(AsO₄)(OH).

Vein
It is a tabular or sheet-like assemblage of minerals which has been intruded into a joint or fissure in rocks.

Venting
It is a term used when hot gasses or lava escape from the crust of the earth.

Vitrinite
It is one of the main groups of macerals which make coal.

Vitreous (luster)
It is a term for that luster of minerals which have reflective properties similar to a glass.

Vitriol
Synonym of sulfuric acid.

Volatilize
It is a term given to disappear as fumes.

Volcanic
One which have originated from a volcano.

Volcano
It is a vent in the earth's crust that spits out molten rock, also known as lava, ash, and gases.

Volcanogenic massive sulphide, (VMS)
It is an ore deposit which typically comprises of a lens of massive sulphide minerals, more than 60% sulphide, formed by the volcanic processes basically on the sea-floor. VMS deposits are important sources of lead, copper and zinc.

Vug
It is a cavity in rock being lined with long and slender crystals. It is formed in the cooling magma, air pockets are formed and simultaneously allows crystals to form in the hollow area.