mineral

Likely raw epidote or altered amphibole crystal

Epidote, Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH); identification is tentative from the image

AI-generated identification · may be incorrect

Dark pistachio-green to brown, vitreous-to-resinous luster, elongated/prismatic form with uneven termination and no obvious cleavage. Epidote has Mohs hardness 6–7 and specific gravity about 3.3–3.5; the specimen appears small and naturally rough.

Identified August 16, 2026More mineral →

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Physical properties

Formation & geological history

Epidote forms in low- to medium-grade metamorphic rocks, hydrothermal veins, and altered igneous rocks, commonly during regional metamorphism from the Paleozoic to present. It may also occur as a secondary mineral in mafic rocks.

Uses & applications

Used mainly as a collector mineral and occasionally as a minor gemstone; it has little industrial or construction use.

Geological facts

Its characteristic pistachio-green color reflects iron substitution, and crystals are commonly strongly elongated. Similar dark green specimens may be amphibole, tourmaline, or chlorite, so chemical or crystallographic testing is needed for certainty.

Field identification & locations

Common localities include Austria, Pakistan, Norway, Mexico, the United States, and New Zealand. Check streak (typically gray-white), hardness, density, and crystal cleavage; avoid relying on color alone.