Augite

Upper left crystal: 5 mm. Dispatched augite crystals. Two crystals at the left are terminated by pointed pyramidal faces. Two crystals at the center are tabular by the (010?) face. The specimen at the lower right is an X-shaped twin, and the specimen at the upper right is a radial group of more than 3 single crystals.

Recovered from tuff breccia erupted from a terrestrial volcano. Formed in the early Pleistocene (2.0 Ma).

Augite from this location was described in 1923.