Quartz (Japan-Law twinned), Arsenopyrite

Superb large plate of sharp, transparent quartz crystals in which two large, undamaged Japan-law twins rest of a matrix of typical prismatic quartz crystals. Many of the quartz crystals have unusual inclusions of silvery arsenopyrite, and small black sphalerite crystals studded about this large piece add great contrast. A superb quartz specimen from the Kami mine in Bolivia, a noted worldwide locality for Japan-law twinned quartz. Mark Cross photo.