Pyroxene

Pyroxene group

The pyroxenes are single-chain silicates — a workhorse family of igneous and metamorphic rocks that includes augite, diopside, enstatite, and the lithium-ore spodumene. The group's field signature is two cleavage directions meeting near 87°, the quick test that separates a pyroxene from the similar-looking amphiboles (which cleave near 124°). Collector interest centers on gemmy members: chrome diopside's vivid green and spodumene's gem varieties kunzite and hiddenite.