Boracite (rare large, polished cabochon)

Item Description

The finest and richest examples of Boracite, a rare borate, came from the famous Boulby Mine, an underground English potash and salt mine. Much of the Boracite was found in the finds of the early to mid 1990s, with none since. This attractive cabochon, having a mass of 6 grams, shows the sharp form of the Boracite crystals frozen within the classically sea-green veins that run through the piece. This is a very rich, unusually presented specimen for the species and this classic locality. Three really interesting and surprising side notes about Boracite: it is strongly piezoelectric and pyroelectric and has a hardness of 7-7.5, both of which you would never normally think of when you think of an evaporite mineral, and it can form pseudomorphs after Quartz, another happenstance that would never cross your mind. Imagine how corrosive THAT chemical environment must be. Recently deaccessed from the Tim Sherburn collection. Tim, through friends who collected this material, was one of the largest sources selling these into the USA market at the time. This is a spectacularly weird, rare cabochon !