metamorphic
Epidote
Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
Hardness: 6-7 Mohs; Color: Pistachio green, yellowish-green, or brownish-green; Luster: Vitreous to resinous; Crystal structure: Monoclinic; Cleavage: Perfect in one direction; Specific gravity: 3.3 to 3.5.
- Hardness
- 6-7 Mohs
- Color
- Pistachio green, yellowish-green, or brownish-green
- Luster
- Vitreous to resinous
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 Mohs; Color: Pistachio green, yellowish-green, or brownish-green; Luster: Vitreous to resinous; Crystal structure: Monoclinic; Cleavage: Perfect in one direction; Specific gravity: 3.3 to 3.5.
Formation & geological history
Forms during low-to-medium grade regional metamorphism of calcium-rich rocks like basalt, gabbro, or limestone. It also occurs in hydrothermal veins and contact metamorphic zones.
Uses & applications
Used primarily as a collector's mineral and sometimes as a semi-precious gemstone. In massive forms (like Unakite), it is used for decorative carvings, beads, and architectural stone.
Geological facts
The name 'Epidote' is derived from the Greek word 'epidosis', meaning 'addition', referring to its crystal geometry with one side longer than the other at the base of the prism.
Field identification & locations
Identify in the field by its distinct 'pistachio' green color. It is commonly found in metamorphic terrains such as the Alps, United States (California, North Carolina), and Brazil. It often co-occurs with quartz and feldspar.
More like this
