Chambersite: Gemstones Information
Chambersite, Mn3B7O13Cl, is unlikely to rank high in the gem world since material of sufficient size for cutting has (so far) been found only at one site, the Barber’s Hill salt dome, Mont Belvieu, Chambers County, Texas,USA. The very small transparent stones recovered have been pale brown to deep purple with a hardness of 7, SG 3.49, RI 1.732, 1.737, 1.744 for the alpha, beta and gamma rays respectively. The birefringence is 0.012,biaxial positive. The orthorhombic crystals are pseudocubic. Recovery which entails descent into brine–diving equipment is necessary.