mineral

Almandine garnet crystal

Almandine, an iron-aluminum garnet; ideal formula Fe₃Al₂(SiO₄)₃

AI-generated identification · may be incorrect

Dark reddish-brown, vitreous to resinous luster, commonly dodecahedral; Mohs hardness 7–7.5, no cleavage, specific gravity about 4.1–4.3. The image shows a small, naturally faceted crystal, though color and species cannot be confirmed from appearance alone.

Identified October 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms during metamorphism of iron- and aluminum-rich rocks, especially schist and gneiss; garnet-bearing rocks occur across a wide range of geological ages.

Uses & applications

Garnet is used as an abrasive and, when transparent and well colored, as a gemstone; opaque crystals are mainly collected.

Geological facts

Garnets are a mineral group, not a single mineral, and their crystal habit often produces distinctive many-sided crystals.

Field identification & locations

Look for a dense, hard, dark red-brown crystal with dodecahedral faces in metamorphic rocks or stream gravels. Common in India, Sri Lanka, Madagascar, and parts of the United States.