noun
amphibole
A group of rock-forming silicate minerals; a technical term in mineralogy.
角閃石は、火成岩や変成岩によく含まれる鉱物です。
Amphibole is a mineral commonly found in igneous and metamorphic rocks.
The Japanese term 角閃石 is a compound of 角 (kaku, 'angle') and 閃石 (senseki, 'amphibole'), reflecting the mineral's characteristic cleavage angles. The exact historical derivation is uncertain.