Mineral Species: Colemanite

Chemical Formula: Ca2B6O11.5H2O

Chemical Name: Hydrous Calcium Borate

Mineral Class: Borate

Mineral Notes: Colemanite is ususally found with Borax in large lake deposits in dry regions, for example the California Playa lakes. It is ususally white and characterised by its brilliant luster.

Description: This specimen is a good example of the mineral. It is a cluster of several transparent crystals which have fused together. The luster is very bright, a trademark of this rather unusual mineral. A nice miniature specimen of good quality.

Location: Borax Pit No11, Boron, California, USA.