Comparison · Precious Stones vs Semi-Precious Stones
Ruby vs Spinel
Ruby and Spinel are easy to confuse. Ruby is harder (Mohs 9) than Spinel (Mohs 8), so Ruby will scratch Spinel and not the other way round. It scratches glass, steel and even quartz; only harder gems will mark it. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Ruby and Spinel
- Ruby is harder (Mohs 9) than Spinel (Mohs 8), so Ruby will scratch Spinel and not the other way round. It scratches glass, steel and even quartz; only harder gems will mark it.
- They overlap in red and pink, but Spinel also comes in blue, purple, orange, and black.
- Well-formed crystals give it away: Ruby is trigonal, Spinel is cubic.
Ruby vs Spinel properties
| Property | Ruby | Spinel |
|---|---|---|
| Type | Precious Stones | Semi-Precious Stones |
| Mohs hardness | 9 | 8 |
| Luster | adamantine | vitreous |
| Streak | White | White |
| Transparency | transparent | transparent |
| Specific gravity | 4 | 3.6 |
| Crystal system | trigonal | cubic |
| Common colors | Red, Pinkish Red, Purplish Red | Red, Pink, Blue, Purple, Orange, Black |
| Rarity | rare | uncommon |
| Typical specimen value | $1000–$100000+ | $100–$10000+ |
Which is more valuable?
Ruby is usually the more valuable of the two: a typical collector specimen runs about $10000 against $500 for Spinel, and premium Ruby can reach $100000 or more.
About Ruby
Ruby is a red variety of corundum, the second hardest natural mineral. Its intense red color comes from chromium impurities.
About Spinel
Spinel was historically mistaken for ruby and sapphire. The 'Black Prince's Ruby' in the British Crown Jewels is actually a spinel.
Ruby vs Spinel FAQ
Is Ruby the same as Spinel?
No. Ruby is a precious stone while Spinel is a semi-precious stone. Ruby is harder (Mohs 9) than Spinel (Mohs 8), so Ruby will scratch Spinel and not the other way round. It scratches glass, steel and even quartz; only harder gems will mark it.
How can you tell Ruby from Spinel?
Ruby is harder (Mohs 9) than Spinel (Mohs 8), so Ruby will scratch Spinel and not the other way round. It scratches glass, steel and even quartz; only harder gems will mark it. They overlap in red and pink, but Spinel also comes in blue, purple, orange, and black. Well-formed crystals give it away: Ruby is trigonal, Spinel is cubic.
Which is harder, Ruby or Spinel?
Ruby is harder: Mohs 9 against Mohs 8 for Spinel.
Which is more valuable, Ruby or Spinel?
Ruby is usually the more valuable of the two: a typical collector specimen runs about $10000 against $500 for Spinel, and premium Ruby can reach $100000 or more.
