mineral

Epidote

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

Hardness: 6-7 on Mohs scale. Color: Pistachio-green to yellowish-green. Luster: Vitreous (glassy). Crystal structure: Monoclinic. Cleavage: Perfect in one direction. Specific gravity: 3.3 to 3.5.

Hardness: 6-7 on Mohs scale
Color: Pistachio-green to yellowish-green
Luster: Vitreous (glassy)

Identified March 24, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6-7 on Mohs scale. Color: Pistachio-green to yellowish-green. Luster: Vitreous (glassy). Crystal structure: Monoclinic. Cleavage: Perfect in one direction. Specific gravity: 3.3 to 3.5.

Formation & geological history

Formed through regional or contact metamorphism of igneous and sedimentary rocks. It commony appears in hydrothermal veins and altered basalt. It can be found in rocks ranging from the Precambrian era to more recent geological formations.

Uses & applications

Used primarily by mineral collectors for its unique green color. It has limited industrial use but is sometimes used as a minor gemstone (cabochons) or in decorative carvings.

Geological facts

The name comes from the Greek word 'epidosis' meaning 'increase', referring to the fact that the base of the prism has one side longer than the other. It is a common alteration product of plagioclase feldspar.

Field identification & locations

Identify in the field by its distinct 'pistachio' green color and its occurrence in metamorphic rocks and veins. Common locations include the Austrian Alps, Brazil, and various sites across the United States (California, Alaska).