mineral
Actinolite
Ca2(Mg,Fe)5Si8O22(OH)2
AI-generated identification · may be incorrectHardness of 5.5-6 on the Mohs scale, typically bright to dark green color, vitreous to silky luster, monoclinic crystal system, and good prismatic cleavage.
Identified More mineral →
Explore Actinolite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 5.5-6 on the Mohs scale, typically bright to dark green color, vitreous to silky luster, monoclinic crystal system, and good prismatic cleavage.
Formation & geological history
Formed through regional or contact metamorphism of iron-rich sedimentary rocks and magnesium-rich limestone, often found in schist and greenstone belts.
Uses & applications
Used primarily as a mineral specimen for collectors and occasionally cut into cabochons or beads for jewelry.
Geological facts
Actinolite is a member of the amphibole group and is one of the minerals that can form fibrous asbestos varieties. Its name comes from the Greek word for 'ray', referring to its radiating crystal habit.
Field identification & locations
Identified by its characteristic green color, fibrous or columnar crystal habit, and occurrence in metamorphic terrains. Common global localities include Canada, Austria, and the USA.
