noun
actinolite
A greenish amphibole mineral; a technical term used in geology and mineralogy.
緑閃石は変成岩によく見られる鉱物です。
Actinolite is a mineral commonly found in metamorphic rocks.
From 緑 (りょく, 'green') + 閃石 (せんせき, 'amphibole'), referring to its green color and mineral group.