Mineral Species: Creedite

Chemical Formula: Ca3Al2SO4(F,OH).2H2O

Chemical Name: Hydrated Calcium Aluminum Sulfate Hydroxide Fluoride

Mineral Class: Sulphate

Mineral Notes: Creedite is a moderately rare sulfate found associated with highly oxidized ore bodies. It is easily confused with cobalt-rich Adamite when both are purple. It lacks latter's luster, however, and Adamite's dome termination is not slanted, as Creedite's is. Creedite's purple colour is attractive and the crystal form is unique, making Creedite an attractive mineral.

Description: A grey matrix on which sit several spherical clusters of Creedite. These are made of radiating needle-like crystals with the unusual terminations. The colour is a very intense purple and the mineral has a very shiny gemmy luster.

Location: New Liberty Mine, Nevada, USA.