Comparison · Semi-Precious Stones
Spinel vs Tanzanite
Spinel and Tanzanite are easy to confuse because both are semi-precious stones. Spinel is harder (Mohs 8) than Tanzanite (Mohs 6.5), so Spinel will scratch Tanzanite and not the other way round. It scratches glass and a steel knife and cannot be scratched by a steel file. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Spinel and Tanzanite
- Spinel is harder (Mohs 8) than Tanzanite (Mohs 6.5), so Spinel will scratch Tanzanite and not the other way round. It scratches glass and a steel knife and cannot be scratched by a steel file.
- They overlap in blue and purple, but Spinel also comes in red, pink, orange, and black.
- Well-formed crystals give it away: Spinel is cubic, Tanzanite is orthorhombic.
Spinel vs Tanzanite properties
| Property | Spinel | Tanzanite |
|---|---|---|
| Type | Semi-Precious Stones | Semi-Precious Stones |
| Mohs hardness | 8 | 6.5 |
| Luster | vitreous | vitreous |
| Streak | White | White |
| Transparency | transparent | transparent |
| Specific gravity | 3.6 | 3.35 |
| Crystal system | cubic | orthorhombic |
| Common colors | Red, Pink, Blue, Purple, Orange, Black | Blue, Violet, Purple |
| Rarity | uncommon | legendary |
| Typical specimen value | $100–$10000+ | $300–$10000+ |
Which is more valuable?
Tanzanite is usually the more valuable of the two: a typical collector specimen runs about $1000 against $500 for Spinel, and premium Tanzanite can reach $10000 or more.
About Spinel
Spinel was historically mistaken for ruby and sapphire. The 'Black Prince's Ruby' in the British Crown Jewels is actually a spinel.
About Tanzanite
Tanzanite is a blue-violet variety of zoisite found only in Tanzania. It's 1,000 times rarer than diamond and was only discovered in 1967.
Spinel vs Tanzanite FAQ
Is Spinel the same as Tanzanite?
No. Both are semi-precious stones, but they are distinct species with different hardness, streak or luster. Spinel is harder (Mohs 8) than Tanzanite (Mohs 6.5), so Spinel will scratch Tanzanite and not the other way round. It scratches glass and a steel knife and cannot be scratched by a steel file.
How can you tell Spinel from Tanzanite?
Spinel is harder (Mohs 8) than Tanzanite (Mohs 6.5), so Spinel will scratch Tanzanite and not the other way round. It scratches glass and a steel knife and cannot be scratched by a steel file. They overlap in blue and purple, but Spinel also comes in red, pink, orange, and black. Well-formed crystals give it away: Spinel is cubic, Tanzanite is orthorhombic.
Which is harder, Spinel or Tanzanite?
Spinel is harder: Mohs 8 against Mohs 6.5 for Tanzanite.
Which is more valuable, Spinel or Tanzanite?
Tanzanite is usually the more valuable of the two: a typical collector specimen runs about $1000 against $500 for Spinel, and premium Tanzanite can reach $10000 or more.
