| Alloy |
|
A mixture of two elements, at least one of which is a metal, which form a new metal with desired properties. |
| Atom |
|
The smallest unit of an element that retains its properties. |
| Conductivity |
|
The ability of a mineral to transmit heat, electricity, or sound. |
| Compound |
|
A naturally-occurring combination of two or more elements in a specific ratio. Compounds need a chemical change to separate into their constituent parts. |
| Corrosion |
|
Gradual chemical destruction of a mineral. Corrosion often, but not always, operates through oxidation. Tarnish is a form of corrosion. |
| Crystal |
|
A unit of a mineral that has a symmetrical shape with flat, angled surfaces. The shape arises from an orderly arrangement of the mineral's atoms. Crystals can aggregate to form distinctive overall shapes. |
| Density |
|
The average mass per unit volume of a substance. |
| Deposit (mineral) |
|
A natural concentration of a mineral in Earth's crust. |
| Ductility |
|
The ability of a mineral to be pulled into wire. |
| Element (chemical) |
|
A substance that cannot be broken down into simpler substances by chemical means. Elements are composed of a single kind of atom. |
| Fineness |
|
A measure of the amount of pure gold in a metal, in parts per thousand. |
| Gold standard |
|
A system in which currency can be redeemed for a fixed amount of gold. The bank or government must have enough gold in reserve to redeem all its circulating currency. |
| Karat |
|
A measure of the amount of pure gold in a metal. One karat is 1/24th of the total weight of the object. 100 percent pure gold is 24 karats. |
| Luster |
|
The manner in which a mineral reflects light. |
| Hardness |
|
A measure of how hard or soft a mineral is relative to diamond, the hardest mineral on the 10-point Mohs scale of hardness. |
| Hydrothermal fluids |
|
Hot water, steam, and gases trapped in fractured or porous rocks underneath Earth's surface. |
| Malleability |
|
A mineral's ability to be hammered into thin sheets. |
| Mass |
|
A measure of the total amount of matter in a body. |
| Metal |
|
A class of elements that have characteristic physical properties. Metals are generally good conductors, and are reflective, malleable, and ductile. |
| Mineral |
|
A solid substance with a crystal structure that formed via geologic processes. Minerals can be either elements or compounds. |
| Mixture |
|
A combination of two substances that can be separated by a physical change. |
| Native element |
|
The pure or nearly pure form of an element found in nature. |
| Nugget |
|
A lump of gold found in nature. |
| Ore |
|
Rock from which valuable minerals can be extracted. |
| Oxidation |
|
To become chemically combined with oxygen. |
| Placer |
|
A deposit of valuable minerals in a lake-, river-, or seabed. |
| Rock |
|
Any naturally occurring combination of one or more minerals. |
| Tarnish |
|
To dull the luster of a mineral by exposure to air or dirt. Tarnish is a form of corrosion. |
| Vein |
|
A mineral deposit in a fracture in the Earth. |
| Volume |
|
The amount of space occupied by a three-dimensional object or region of space. |
