hypersthene
/ˈhaɪpərˌsθin/
noun
- A dark, glassy mineral that is a type of pyroxene, often found in igneous and metamorphic rocks.
- The geologist identified hypersthene in the volcanic rock sample.
- The dark streaks in the cliff face were caused by deposits of hypersthene.
- Hypersthene is sometimes used as a gemstone when it displays a silvery sheen.