1. Plural of amphibole; a group of silicate minerals that typically contain water and form elongated crystals, commonly found in igneous and metamorphic rocks.
Usage: geology; mineralogy

Examples

• Amphiboles are dark-colored minerals often found in granite and basalt.
• The geologist identified amphiboles in the thin section of the metamorphic rock.
• Hornblende is one of the most common amphiboles in igneous rocks.
• Amphiboles contain hydroxyl groups in their crystal structure.
• The presence of amphiboles helped determine the cooling history of the magma.