Numanoite

A single crystal fragment of Numanoite, a rare Calcium Copper Borate. The crystal is translucent and white with darker areas in the centre, with vitreous lustre in places. This is from its type location Fuka Mine, Okayama, Japan. Numanoite is normally blueish green, and is the Cu-dominant analogue of Borcarite, with which it forms a partial series, and is often found as the coloured zones with colourless Borcarite. It is possible in this specimen that the white areas are Borcarite, and the darker centre is the Numanoite.