Enargite
Kaize, Sakuho city, Minami-Saku county, Nagano pref., Japan
Field of view: 10 mm. Enargite in an open space of a quartz vein. The prismatic black crystals are enargite with striations parallel to the prism elongation. The surface exhibits a dull luster by weathering. The prism is terminated by (001) face. The tiny clear crystals at the left end are prismatic crystals of gangue quartz. The earthy white parts in the intestices of enargite are clay.
Recovered from an open space of a quartz vein in a hydrothermal deposit associated with pyrophyllitization hydrothermal alteration. Formed in the late Miocene (11 Ma).
Enargite from this location was described in 1947.
Other localities
- Hongo Mine (Hydrothermal, Prismatic)
- Masutomi Mine (Hydrothermal, Prismatic)