mineral
Garnet
Garnet-group silicate, likely almandine–spessartine; general formula X₃Y₂(SiO₄)₃
AI-generated identification · may be incorrectTypically deep red-brown with a vitreous luster, granular texture, and no cleavage; hardness 6.5–7.5 Mohs, cubic crystal system, and specific gravity about 3.5–4.3. The specimen appears naturally irregular or roughly tumbled, with dark inclusions and reflective crystal faces.
Identified More mineral →
Explore Garnet in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Typically deep red-brown with a vitreous luster, granular texture, and no cleavage; hardness 6.5–7.5 Mohs, cubic crystal system, and specific gravity about 3.5–4.3. The specimen appears naturally irregular or roughly tumbled, with dark inclusions and reflective crystal faces.
Formation & geological history
Garnet forms in metamorphic rocks such as schist and gneiss, and in some igneous rocks and placer deposits; its age depends on the host rock, commonly Paleozoic to Precambrian. It crystallizes under elevated temperature and pressure during regional metamorphism.
Uses & applications
Used as an abrasive in sandpaper, waterjet cutting, and filtration; transparent red varieties are cut as gemstones. Common rough specimens generally have modest collecting value.
Geological facts
Red garnet is commonly almandine, though composition is often mixed; color varies with iron and manganese content. Garnet’s lack of cleavage makes it durable and useful as an abrasive.
Field identification & locations
Identify it by its wine-red to brown color, glassy luster, high density, absence of cleavage, and commonly rounded dodecahedral or trapezohedral crystals; streak is usually white. Common sources include India, Sri Lanka, Madagascar, the United States, and metamorphic terrains worldwide.
