Garnet

Almandine (Fe3Al2(SiO4)3)

Rock Type: mineral

Garnet

Physical Properties

Mohs hardness 6.5-7.5, deep red to brownish-black color, vitreous to resinous luster, isometric crystal system, dodecahedral habit, no true cleavage, specific gravity 3.5-4.3

Formation & Geological History

Formed primarily in metamorphic rocks like schist and gneiss through regional metamorphism. Common in high-pressure and high-temperature environments throughout many geological ages.

Uses & Applications

Used extensively as an industrial abrasive for waterjet cutting and sandblasting. High-quality specimens are used in jewelry (January birthstone) and as collector mineral specimens.

Geological Facts

Garnets are not just red; they come in almost every color except blue. The name 'garnet' comes from the Latin 'granatus' (grain), possibly a reference to Punica granatum (pomegranate).

Field Identification & Locations

Identify in the field by its characteristic dodecahedral crystal shape and relatively high hardness. Commonly found in metamorphic terrains such as the Adirondack Mountains or the Alps.

Identified on: 5/9/2026

Mode: Standard