Tourmaline is a very complex mineral group with a wide variety of colors.

Chemical Formula: Variable
Class: Silicates, Cyclosilicates
Hardness: 7-7.5
Coloration: All colors of the spectrum as well as colorless and black.

How to identify it/Unique Characteristics or Properties: This is a very complex mineral group with a wide variety of colors, but all are crystals with a triangular or close to triangular cross section. Often has banded colors, with one color blending into another along the length of the crystal. Each color has its’ own name, as they often resemble other gemstones. Can grow up to a meter long and several inches wide.

Where to find it in…

The Northwest: California
Other: Found all over the world. New England, Canada, Mexico, Brazil, Australia, Afghanistan, and much more.
Past Uses: Mainly used for cheaper gemstones as the color can imitate anything from rubies to sapphires. It is also used in optical devices and some depth sounding equipment.
How it was Made: The crystals form best in limestone which is in contact with granite. It requires high pressure.
Interesting Facts: It is the state gem of Maine. Tourmaline can be electrically charged by heating it.