Danburite

A truly superb cabinet specimen of large terminated Danburite crystals measuring to an exceptional 10 cm.  The crystals are translucent white to gemmy, forming a stunning display of sub-vertical crystals with many exhibiting different termination habits, some flat and chisel-like and various tapered pyramidal forms.  All the Danburite prisms contain what first appear as small black inclusions, which at low magnification (say, x5) are revealed as pale brassy Chalcopyrite crystals.  Danburite is a calcium-boron silicate which is sometimes used as a gem mineral.  This magnificent specimen is from the Aurora mine at Charcas in San Luis Potosi state in central Mexico.