metamorphic

Epidote

Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

AI-generated identification · may be incorrect

Hardness: 6-7 Mohs; Color: Pistachio-green to yellowish-green; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Perfect in one direction; Specific gravity: 3.3 to 3.5.

Hardness: 6-7 Mohs
Color: Pistachio-green to yellowish-green
Luster: Vitreous to pearly

Identified July 19, 2026More metamorphic →

Explore Epidote in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6-7 Mohs; Color: Pistachio-green to yellowish-green; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Perfect in one direction; Specific gravity: 3.3 to 3.5.

Formation & geological history

Formed through low-grade regional or hydrothermal metamorphism of mafic rocks, such as basalt or gabbro, and sometimes within marble or skarn deposits.

Uses & applications

Primarily used as a minor gemstone for jewelry when transparent, a decorative stone, and a collectible mineral specimen for geological study.

Geological facts

Epidote is known for its distinct 'pistachio' green color. Its name comes from the Greek word 'epidosis', meaning 'addition', in reference to one side of the ideal prism being longer than the other.

Field identification & locations

Identify by its unique yellowish-green color and hardness. It is commonly found in metamorphic rocks alongside quartz, feldspar, and chlorite. Frequent locations include the Alps, Norway, and various regions in the USA.