Greenockite

Field of view: 40 mm. Greenockite associated with sphalerite. The powdery yellow crust is greenockite. The black parts exhibiting perfect cleavage are sphalerite. Other parts are limonite dirt.

Recovered from a meteoric oxidation zone of a moderate-temperature hydrothermal deposit combined with skarn formed by contact metamorphism of I-type (magnetite-series) quartz porphyry.

The first greenockite from Japan was reported from this location in 1903.

Sphalerite generally contains minor amount of Cd replacing Zn, and Cd is concentrated as greenockite in the weathering process by oxidation of Zn-bearing minerals. Artificial Cd is also produced as a by-product of Zn rment.