Arsenopyrite

Field of view: 100 mm. A group of short rhombic prisms of arsenopyrite. Fresh arsenopyrite is silver as seen in the host but it turns dull yellow soon. The silver-white parts at the host are arsenopyrite, and the black parts are sphalerite.

Recovered from an open space of sulfide minerals in a moderately low-temperature hydrothermal deposit combined with skarn formed by contact metamorphism of I-type (magnetite-series) quartz diorite. Formed in the late Miocene (6 Ma).

Arsenopyrite from this location was described in 1918.