mineral

Epidote

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

Hardness: 6-7 Mohs; Color: Pistachio-green to yellowish-green or brownish-green; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Perfect in one direction; Specific gravity: 3.3 to 3.6

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

Identified June 28, 2026More mineral →

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

Formation & geological history

Formed during low-to-medium grade metamorphism of igneous and sedimentary rocks. Often found in contact metamorphic zones, hydrothermally altered basaltic rocks, and schist. Usually associated with quartz, feldspar, and chlorite.

Uses & applications

Primarily of interest to mineral collectors and as a semi-precious gemstone. Occasionally used as an indicator mineral in geological mapping or as an ornamental stone in jewelry.

Geological facts

The name 'Epidote' is derived from the Greek word 'epidosis' meaning 'increase', referring to the base of the crystal being longer on one side. It is the signature mineral of the 'Epidote-Amphibolite' metamorphic facies.

Field identification & locations

Identify in the field by its distinct pistachio-green color and hardness (it can scratch glass). Found globally, with notable deposits in Norway, Italy, Mexico, and the USA. Collectors look for elongated, prismatic crystals.