CHALCOPYRITE ON PYRITE

Sulfide minerals from this region of Japan are both beautiful and very difficult to find on the market. This combination features sharp chalcopyrite crystals - many of them twinned - interspersed with traces of marcasite and cubic pyrite, all atop a pyrite matrix. The backside of the matrix has rounded negative casts that give it a neat and unique look. As far as Japanese localities go, the Kosaka Mine is a lesser known one, beginning operations all the way back in the Edo period and operating intermittently until the 1970's. This is a RARE example, likely dating all the way back to the 1800's and is a fine and important representation of both the species and of the sulfide minerals to come out of Akita Prefecture.