Welcome to the Mineral and precious stone glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z  All terms

Room or complex containing scientific equipment used for research and tests.

The present term describing something displaying labradorescence.

Effect which causes dark, metallic-like color shimmers, commonly blue and green, to be displayed on a few minerals. The name is derived from Labradorite, a mineral which is the best example of this effect.

Lenticular mass of igneous rock stuck between layers of sedimentary rock.

Sedimentary rocks consisting of many thin layers.

See rare earth elements

An individual who facets gemstones as a trade, and the shop of such an individual. Also used in adjective form when relating to gems (i.e. lapidary equipment).

Molten rock on the surface of the earth released from a volcano.

Lens shaped. When applied to minerals it refers to concretions or nodules that have a flattened, lens-like shape

Paper with powder extracted from certain plants that tests the pH of a substance. Acid turns red while base turns blue; neutral remains white. The stronger the acid or base, the more intense red or blue the color of the litmus paper turns.

Area where a specific mineral was found or occurs.

Vein of precious metal.

A wavelength of ultraviolet light. Some minerals display fluorescence when exposed to longwave ultraviolet light. (See Fluorescence in mineral properties for more information). See also shortwave. Commonly abbreviated as LW.

Small magnifying lens used to observe certain aspects of a gemstone. Loupes usually have a magnification level of 10x.

Material that can reduce friction. Used as a coating on objects that are subject to friction.

To give off light under certain conditions. See luminescence.

General term describing the capability of a mineral with a habit of giving off light when put under certain conditions. Three examples of luminescence are fluorescence, triboluminescence, and thermoluminescence.

General term describing any mineral capable of giving off light when put under certain conditions. Three examples of minerals that are luminescent are minerals that exhibit fluorescence, triboluminescence, and thermoluminescence.

The exhibition of the surface of minerals, including their reflective properties. (See luster in mineral properties for more information.)