Mining Glossary O

Odd lot - A block of shares that is less than a board lot.

Open order - An order to buy or sell stock, which is good until cancelled by the client.

Open pit - A mine that is entirely on surface. Also referred to as open-cut or open-cast mine.

Option - An agreement to purchase a property reached between the property vender and some other party who wishes to explore the property further.

Option (on Stock) - The right to buy or sell a share at a set price, regardless of market value.

Ore - A mixture of ore minerals and pangue from which at least one of the metals can be extracted at a profit.

Ore pass - Vertical or inclined passage for the downward transfer of ore connecting a level with the hoisting shaft or a lower level.

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.

Oreshoot - The portion, or length, of a vein or other structure that carries sufficient valuable minerals to be extracted profitably.

Organic maturation - The process of turning peat into coal.

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.

Oxiddtion - A chemical reaction caused by exposure to oxygen that results in a change in the chemical composition of a mineral.