gemstone
Garnet (Polished)
Nesosilicate (Group formula: X3Y2(SiO4)3)
Hardness: 6.5-7.5. Color: Deep red to reddish-brown. Luster: Vitreous to resinous. Crystal structure: Isometric (dodecahedral). Specific gravity: 3.1–4.3.
- Hardness
- 6
- Color
- Deep red to reddish-brown
- Luster
- Vitreous to resinous
Identified More gemstone →
Explore Garnet (Polished) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7.5. Color: Deep red to reddish-brown. Luster: Vitreous to resinous. Crystal structure: Isometric (dodecahedral). Specific gravity: 3.1–4.3.
Formation & geological history
Forms in metamorphic rocks such as mica schist, gneiss, and granulite through high pressure and temperature metamorphosis of shale or clay-rich sedimentary rocks.
Uses & applications
Used primarily in jewelry as a gemstone and as an industrial abrasive for sandblasting and waterjet cutting due to its hardness.
Geological facts
The name 'garnet' comes from the Latin 'granatus' meaning grain, possibly referring to the seeds of a pomegranate. Red garnets are the most common and have been used as gems since the Bronze Age.
Field identification & locations
Commonly found in metamorphic regions like the Adirondack Mountains or parts of India. In the field, look for dodecahedral (12-sided) crystal habits and a distinct 'garnet red' flash against darker matrix rocks.
More like this
Other gemstone specimens
Ammolite
Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)
mineral
Amber
Succinite (Organic Gemstone)
mineral
Emerald
Beryl (Be₃Al₂Si₆Oထ₈) with Chromium/Vanadium impurities
gemstone
Citrine
Silicon Dioxide (SiO2) with iron impurities
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
mineral
Amber
Succinrite (Organic Gemstone)
mineraloid