Rock Identifier
Garnet (Garnet Group (Silicate Minerals), formula varies e.g., Almandine Fe3Al2(SiO4)3) — mineral
mineral

Garnet

Garnet Group (Silicate Minerals), formula varies e.g., Almandine Fe3Al2(SiO4)3

Hardness: 6.5-7.5. Color: Deep reddish-brown to black. Luster: Vitreous to resinous. Crystal structure: Isometric (dodecahedral). Cleavage: None. Specific gravity: 3.5-4.3.

Hardness
6
Color
Deep reddish-brown to black
Luster
Vitreous to resinous
Identified More mineral

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Physical properties

Hardness: 6.5-7.5. Color: Deep reddish-brown to black. Luster: Vitreous to resinous. Crystal structure: Isometric (dodecahedral). Cleavage: None. Specific gravity: 3.5-4.3.

Formation & geological history

Formed primarily in metamorphic rocks like schist and gneiss under high pressure and temperature; also found in some igneous rocks. Ages range from Precambrian to Cenozoic.

Uses & applications

Used as industrial abrasives (sandblasting, waterjet cutting), gemstones in jewelry, and decorative polished spheres or ornaments.

Geological facts

The name 'garnet' comes from the Latin 'granatus' (meaning seed/pomegranate). Garnet has been used as a gemstone since the Bronze Age and is the birthstone for January.

Field identification & locations

Identify in the field by its crystal habit (dodecahedron), high hardness, and lack of cleavage. Often found in micaceous schists or as heavy mineral sand in stream beds.