Kämmererite

Kammererite is a rare chromium-rich variety of Clinochlore and member of the Chlorite family. It crystallizes in the form of masses, pyramid-like micropoints, and hexagonal crystals. The color can range from dark red, to purple, and even violet. This depends on the amount of chromium impurities within. It was first discovered in 1841 by Nils Gustaf Nordenskiöld, a Finnish mineralogist.