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

Form of electromagnetic radiation which contains the shortest wavelength of the spectrum. Gamma rays easily penetrate matter because of their short wavelength. See also alpha and beta waves.

Worthless material in which valuable metals or gems occur.

Sandpaper composed of tiny, hard, Garnet crystals, glued on to it for use as an abrasive.

Instrument that measures intensity of radiation. It is very useful for detecting radioactive minerals.

A cut mineral or pearl refined for use as an ornament.

The science and procedures involved in mining, faceting, and marketing of gemstones.

Individual practicing in the subject of gemology.

Any mineral or naturally occurring substance in an raw, uncut state that is capable of being a gem.

Hollow rock that is filled or partially filled with crystals.

Having to do with geology.

The science and study of the physical structure of the earth, including the areas of rocks and minerals.

Banded or layered metamorphic rock, same in composition to Granite.

Salt made of sodium sulfate (Na2 SO4 ·10H2O) used in the manufacture of paper ,glass and in stomach medications. Glauber's salt is extracted from the mineral Glauberite.

The term globular is used as a synonym of botryoidal, but sometimes describes any rounded agglomeration, such as botryoidal, reniform and mammilary.

Instrument that measures crystal angles.

Individual component belonging to a grainy aggregate.

Weight used in reference to measuring pearls. A grain is .05 grams or ¼ carat.

Crystal aggregate resembling a cluster of grain.

Weight measurement used to measure less valuable gems or rough stones. It corresponds to the measurement of the metric gram.

Accumulation of small, smooth, rounded rock deposited by a stream or river.

The force that attracts matter to the center of the earth. The term gravity is sometimes used as a shortened form of the term specific gravity.

Luster of a mineral that appears coated with grease. Some minerals are coated with chemicals to induce a greasy luster.

1) An aggregate of crystals.
2) Synonym of crystal group.
3) The classification order that minerals are arranged in based on their chemical structure.
4) A scientifically recognized selection of minerals similar in structure. All groups have a specific group name, and individual minerals may also be categorized. A mineral in the group may have the same name as group name. An example is the Olivine Group, which contains the minerals Forsterite, Olivine (also known as Chrysolite), and Fayalite. See also series.