Topaz
Hirukawa, Nakatsugawa city, Gifu pref., Japan
Field of view: 10 mm. Topaz associated with protolithionite. The transparent prisms vertical to the vein wall at the top are topaz. The massive white part with a vitreous luster at the bottom is gangue quartz. The micaceous dark green crystals are protolithionite.
Recovered from a quartz vein in a pneumatolytic deposit formed near the boundary between welded tuff and S-type (Ilmenite-series) granite, members of a caldera complex. Formed in the Late Cretaceous (70 Ma).
Topaz from this location was described in 1979.
Other localities
- Takatori Mine (Pneumatolytic, Prismatic)
- Ichiyanagi Mine (Pneumatolytic, veinlet)
- Mount Yagen (Pneumatolytic, veinlet)
- Hirukawa (Pegmatite, Prismatic)
- Mount Tanakami (Pegmatite, Prismatic)