Ramsdellite

Field of view: 15 mm. Crystals of ramsdellite. The black prisms are ramsdellite. The surrounding massive group of fine dark gray grains is also ramsdellite exhibiting perfect cleavage.

Recovered from an open space of a ramsdellite vein in a moderate-temperature hydrothermal deposit in rhyolite. Formed in the middle Miocene (13 Ma).

Ramsdellite from this location was described in 1973.