mineral

Almandine Garnet

Almandine (Fe3Al2Si3O12)

Hardness: 7-7.5. Color: Dark red to brownish black. Luster: Vitreous to resinous. Crystal structure: Isometric (dodecahedron). Cleavage: None (conchoidal fracture). Specific gravity: 4.1-4.3.

Hardness: 7-7
Color: Dark red to brownish black
Luster: Vitreous to resinous

Identified June 12, 2026More mineral →

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Physical properties

Hardness: 7-7.5. Color: Dark red to brownish black. Luster: Vitreous to resinous. Crystal structure: Isometric (dodecahedron). Cleavage: None (conchoidal fracture). Specific gravity: 4.1-4.3.

Formation & geological history

Formed in regional metamorphic rocks such as mica schists and gneisses under high pressure and temperature conditions. It can also be found in some igneous rocks like granites.

Uses & applications

Used widely as an abrasive (sandpaper, waterjet cutting), a gemstone for jewelry, and as a geological indicator of metamorphic conditions.

Geological facts

Almandine is the most common member of the garnet group. It is sometimes called 'Carbuncle' in historic texts. It is the birthstone for January.

Field identification & locations

Identify by its 'soccer ball' (dodecahedral) shape, high density, and lack of cleavage. Commonly found in metamorphic terrains such as the Adirondacks or the Alps.