Tourmaline has a few properties that can aid in its identification. If you have a tourmaline crystal, identification should be easy.

• Tourmaline has a prismatic crystal habit and often has obvious striations that parallel the long axis of a crystal.
• Tourmaline crystals often have triangular or six-sided cross-sections with rounded edges.
• Tourmaline crystals are often color zoned through their cross-sections or along their length.
• Tourmaline can be pleochroic with the darkest color viewing down the C-axis and lighter color viewing perpendicular to the C-axis.

Don’t despair if your suspected tourmaline is an accessory mineral in an igneous or metamorphic rock. It often occurs in these rocks as tiny prismatic crystals. Get a hand lens and look for striations and rounded cross-sections.

Tourmaline has indistinct cleavage, so any specimen with obvious cleavage is probably not tourmaline. Color might not be helpful. The most common tourmaline color is black, but the mineral occurs in all colors of the spectrum.