mineral

Epidote

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

AI-generated identification · may be incorrect

Hardness: 6-7 Mohs; Color: Pistachio-green, yellow-green, or brownish-green; Luster: Vitreous to pearly; Crystal Structure: Monoclinic; Cleavage: Perfect in one direction; Specific Gravity: 3.3-3.6

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

Identified July 17, 2026More mineral →

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Physical properties

Hardness: 6-7 Mohs; Color: Pistachio-green, yellow-green, or brownish-green; Luster: Vitreous to pearly; Crystal Structure: Monoclinic; Cleavage: Perfect in one direction; Specific Gravity: 3.3-3.6

Formation & geological history

Forms through regional metamorphism of calcium-rich igneous rocks or hydrothermal alteration. Commonly found in schists, gneisses, and skarns.

Uses & applications

Primarily a collector's mineral; sometimes used as a minor gemstone (Pistacite) or for decorative beads and carvings.

Geological facts

Epidote is named from the Greek word 'epidosis' meaning 'addition' because one side of the ideal prism is longer than the others. It is a key indicator mineral in low-grade metamorphism.

Field identification & locations

Identify in the field by its characteristic 'pistachio green' color and high hardness. Common in mountainous regions with metamorphic history like the Alps or Blue Ridge Mountains.