mineral

Vesuvianite (Idocrase)

Vesuvianite, Ca10(Mg,Fe)2Al4(SiO4)5(Si2O7)2(OH)4

AI-generated identification · may be incorrect

Olive-green, granular to short-prismatic crystals with vitreous to resinous luster; Mohs hardness 6.5–7, generally poor cleavage, tetragonal crystal system, and specific gravity about 3.3–3.5. The specimen appears to be a natural crystal cluster, though exact identification would benefit from testing.

Identified August 22, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in contact-metamorphosed, calcium-rich rocks such as limestones and skarns, commonly during Mesozoic to younger metamorphic events. It crystallizes from hot, chemically reactive fluids near igneous intrusions.

Uses & applications

Transparent material may be cut as a gemstone; opaque clusters are primarily collector specimens. It has little major industrial or construction use.

Geological facts

Its alternate name, idocrase, comes from Greek roots meaning “mixed form,” referring to its varied crystal habits. Green vesuvianite can resemble epidote, grossular garnet, or diopside.

Field identification & locations

Look for olive-green color, high hardness, resinous luster, and compact tetragonal crystals in marble or skarn. Common localities include California, Quebec, Italy, Pakistan, Russia, and Norway.