mineral

Almandine Garnet

Fe3Al2(SiO4)3

Hardness: 7-7.5 (Mohs), Color: Deep red to reddish-brown, Luster: Vitreous to resinous, Crystal Structure: Isometric (Dodecahedral), Cleavage: None/Indistinct, Specific Gravity: 4.1-4.3

Hardness: 7-7

Identified March 5, 2026More mineral →

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Physical properties

Hardness: 7-7.5 (Mohs), Color: Deep red to reddish-brown, Luster: Vitreous to resinous, Crystal Structure: Isometric (Dodecahedral), Cleavage: None/Indistinct, Specific Gravity: 4.1-4.3

Formation & geological history

Primarily formed in regional metamorphic rocks like mica schists and gneisses during high-pressure and high-temperature conditions. It can also appear in contact metamorphic rocks and some igneous rocks.

Uses & applications

Commonly used as a gemstone in jewelry (cabochons or faceted), and industrially as an abrasive for sandblasting and water-jet cutting due to its hardness and lack of cleavage.

Geological facts

Almandine is the most common member of the garnet group. It was historically called 'carbuncle' when cut as a cabochon. Large crystals are often found in the Adirondack Mountains of New York.

Field identification & locations

Identified by its deep red color and high hardness (scratching glass). In the field, look for well-defined 12-sided dodecahedral crystals in metamorphic schist in locations like Idaho, USA, or Madagascar.