This huge size kernite specimen is formed by some glassy and translucent cleavage crystals. It is a rare borate, named after the namesake California county where it was discovered. It is extremely rare in sharp crystals. These crystals are not formed in the borate deposit itself, but rather in the tanks that are used to dissolve the borax. Every few years the tanks are shut down for maintenance. Kernite and primary tincalconite crystals are found growing on the large stirring blades and the walls of the tank. From the former Renaud Vochten collection (label will be send to the buyer).