noun
- A dark silicate mineral that occurs in many igneous and metamorphic rocks, typically containing calcium, magnesium, iron, and aluminum.
Usage: geology; mineralogy
Examples
- Amphibole is a common constituent of granite and basalt.
- The geologist identified amphibole crystals in the thin section of the rock sample.
- Hornblende is the most abundant variety of amphibole found in igneous rocks.
- Amphibole minerals are characterized by their double-chain silicate structure.
- The presence of amphibole in the metamorphic rock indicated high-pressure conditions during formation.