How to Identify Garnet: Hardness, Streak, Luster and Tests
Quick answer
Garnet (mineral): 6 identifying properties, 1 home test, quoted from geology department and survey sources.
Updated 2026-09-10 · Sources: University of Minnesota Common Minerals
Found one? Take a photo to identify it.
Download on the App StoreWhat are the key facts?
- Type: Mineral
- Mohs hardness: 6.5–7.5 (very hard)
- Streak: White, or a pale shade of the sample's own color.
- Luster: Vitreous to resinous luster; transparent to translucent.
- Color: Dark red to reddish brown is most common; also occurs in reddish purple, brown, black, emerald green, and even white.
- Cleavage or fracture: No cleavage.
- Specific gravity: 3.6–4.3, increasing with iron content
What Garnet looks like
The properties that identify Garnet — mohs hardness: 6.5–7.5 (very hard); streak: White, or a pale shade of the sample's own color; luster: Vitreous to resinous luster; transparent to translucent; color: Dark red to reddish brown is most common; also occurs in reddish purple, brown, black, emerald green, and even white; cleavage or fracture: No cleavage; specific gravity: 3.6–4.3, increasing with iron content. Hardness, streak and cleavage are the reliable ones; color alone rarely settles it.
Tests you can do at home
- Crystal-form test: commonly forms dodecahedrons (twelve-sided) or trapezohedrons (twenty-four-sided).
Where it is found in North America
A common accessory mineral in Precambrian granites, schists, and gneisses across the Upper Midwest; more typical of high-grade metamorphic rocks.
How to photograph it for identification
Photograph a fresh, unweathered surface in daylight, then a second shot of any crystal faces or broken edge. Include a coin for scale. If you did a streak test, photograph the streak next to the specimen. The app suggests the likely mineral or rock; confirm with hardness and the tests above before you label it.
FAQ
How hard is Garnet on the Mohs scale?
6.5–7.5 (very hard). A fingernail is about 2.5, a copper coin about 3, a steel knife 5.5 and glass about 5.5, so test against those.
What color streak does Garnet leave?
White, or a pale shade of the sample's own color. Rub the specimen on an unglazed porcelain tile; the powder color is the streak, and it is more consistent than the specimen color.
What is the simplest test for Garnet?
Crystal-form test: commonly forms dodecahedrons (twelve-sided) or trapezohedrons (twenty-four-sided).
More in Rock and Mineral Identification Reference
- How to Identify Quartz: Hardness, Streak, Luster and Tests
- How to Identify Orthoclase (Potassium Feldspar): Hardness, Streak, Luster and Tests
- How to Identify Plagioclase Feldspar: Hardness, Streak, Luster and Tests
- How to Identify Calcite: Hardness, Streak, Luster and Tests
- How to Identify Muscovite (White Mica): Hardness, Streak, Luster and Tests
- How to Identify Biotite (Black Mica): Hardness, Streak, Luster and Tests
- How to Identify Pyrite (Fool's Gold): Hardness, Streak, Luster and Tests
- How to Identify Magnetite: Hardness, Streak, Luster and Tests
- How to Identify Hematite: Hardness, Streak, Luster and Tests
- How to Identify Galena: Hardness, Streak, Luster and Tests
- How to Identify Fluorite: Hardness, Streak, Luster and Tests
- How to Identify Gypsum: Hardness, Streak, Luster and Tests
Related
See what's actually under your feet.
Start with a single scan.
Found one? Take a photo to identify it.
Sources
- University of Minnesota Common Mineralscommonminerals.esci.umn.edu/minerals-g-m/garnet
Compiled by the RockLens editorial team
Every fact on this page is taken from the sources listed above; numbers and prices are copied from the source, and prices name the guide or auction and its date. Research and drafting were assisted by AI, and each claim was then checked against the cited sources. Checked 2026-09-10. We do not buy, sell or grade items; the app identifies what you photograph and points you to these references.