Spinel
| Colour | Red, Blue, Black, Pink, Purple, Green, Brown |
|---|---|
| Mohs hardness | 7.5–8.0 |
| Lustre | Vitreous |
| Streak | White |
| Crystal system | Cubic |
| Transparency | Transparent to opaque |
| Cleavage | None |
| Fracture | Conchoidal |
| Specific gravity | (Depending on the composition) The rare Zn-rich spinel can be as high as 4.40, otherwise it averages from 3.58 to 3.61 |
What is Spinel?
Spinel is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4 in the cubic crystal system. The name comes from the Latin word spinella, a diminutive form of spine, in reference to its pointed crystals.
How to identify Spinel
- Lustre: Vitreous.
- Hardness: Mohs 7.5–8.0 — hard enough to scratch glass.
- Streak: White.
- Habit: Cubic crystal system.
Spinel value
Spinel is a fine gemstone priced per carat by quality — colour, clarity, cut, carat and origin — not by weight in grams. Typical market ranges:
| Quality | Price per carat |
|---|---|
| Commercial | $50–$600 / ct |
| Good | $500–$3,000 / ct |
| Fine | $1,500–$12,000 / ct |
| Top | $8,000–$18,000 / ct |
Ranges cross-validated across two independent research passes against gemstone price guides, 2026-06 — sources: ajsgem.com, gem-matrix.com. Colour saturation, clarity, cut and origin move the price enormously, and treatments or lab-grown stones sell for a fraction — so this is a guide, not an appraisal. Have anything valuable checked by a certified gemmologist. See the full crystal & gemstone value guide.
