RocksdayGarnet vs Spinel
How to tell them apart
A family of silicate minerals that grow as round, many-faced crystals. Deep red almandine studding schist is the classic find.
Photo: Moha112100, CC BY-SA 3.0
A hard magnesium aluminum oxide that forms sharp octahedral crystals — long confused with ruby.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
Key differences
- Garnet forms rounded dodecahedra.
Side by side
| Property | Garnet | Spinel |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 7–7.5 | 7.5–8 |
| Luster | Vitreous | Vitreous |
| Streak | White | White |
| Colors | Red, Brown | Red, Pink, Blue, Purple, Black |
| Crystal system | Cubic | Cubic |
| Specific gravity | 3.9–4.3 | 3.58–3.61 |
| Formula | Fe₃Al₂(SiO₄)₃ (almandine) | MgAl₂O₄ |
| Found in | Gore Mountain, New York; Emerald Creek, Idaho | Mogok, Myanmar; Badakhshan, Tajikistan |
Properties that are the same for both are grayed out.
How to identify garnet
- Ball-shaped crystals with 12 or 24 faces.
- Deep wine-red to brown.
- Scratches glass.
- Often embedded in mica schist.
Crystal system: Cubic
Full Garnet guide →How to identify spinel
- Sharp eight-sided octahedrons, often in marble.
- Hardness about 8.
- Red, pink, blue or purple with a bright glassy luster.
Crystal system: Cubic
Full Spinel guide →More comparisons
Could you tell them apart from a blurry close-up?
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