Henmilite on Olshanskyite

Equant, azure to deep inky-blue crystals of the calcium-copper borate Henmilite are scattered over the surface of snowy-white botryoidal Olshanskyite from the Fuka mine in Okayama Prefecture, Honshu Island, Japan. Fuka mine is the type locality for Henmilite and this occurs as well developed individual crystals ranging between 1 and 3 mm. Olshanskyite is a rare calcium borate of low density (about 2.2 RD) and occurs here at the Fuka mine as a chalk-like mass with a low relief botryoidal surface. This is a very fine specimen of both these rare minerals.