Comparison · Minerals vs Precious Stones
Kyanite vs Sapphire
Kyanite and Sapphire are easy to confuse. Sapphire is harder (Mohs 9) than Kyanite (Mohs 5), so Sapphire will scratch Kyanite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Kyanite and Sapphire
- Sapphire is harder (Mohs 9) than Kyanite (Mohs 5), so Sapphire will scratch Kyanite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
- Hold a thin edge to the light: Kyanite is translucent, Sapphire is transparent.
- They overlap in blue, green, and orange, but Kyanite also comes in black and Sapphire also comes in pink, yellow, and white.
- Well-formed crystals give it away: Kyanite is triclinic, Sapphire is trigonal.
Kyanite vs Sapphire properties
| Property | Kyanite | Sapphire |
|---|---|---|
| Type | Minerals | Precious Stones |
| Mohs hardness | 5 | 9 |
| Luster | vitreous | adamantine |
| Streak | White | White |
| Transparency | translucent | transparent |
| Specific gravity | 3.6 | 4 |
| Crystal system | triclinic | trigonal |
| Common colors | Blue, Green, Orange, Black | Blue, Pink, Yellow, Orange, Green, White |
| Rarity | uncommon | rare |
| Typical specimen value | $10–$300+ | $500–$50000+ |
Which is more valuable?
Sapphire is usually the more valuable of the two: a typical collector specimen runs about $5000 against $50 for Kyanite, and premium Sapphire can reach $50000 or more.
About Kyanite
Kyanite is a blue silicate mineral unique for having different hardness values depending on the direction of scratch (4-5 lengthwise, 6-7 crosswise).
About Sapphire
Sapphire is a variety of corundum in any color except red. Blue sapphires are most prized, especially the legendary Kashmir stones.
Kyanite vs Sapphire FAQ
Is Kyanite the same as Sapphire?
No. Kyanite is a mineral while Sapphire is a precious stone. Sapphire is harder (Mohs 9) than Kyanite (Mohs 5), so Sapphire will scratch Kyanite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
How can you tell Kyanite from Sapphire?
Sapphire is harder (Mohs 9) than Kyanite (Mohs 5), so Sapphire will scratch Kyanite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Hold a thin edge to the light: Kyanite is translucent, Sapphire is transparent. They overlap in blue, green, and orange, but Kyanite also comes in black and Sapphire also comes in pink, yellow, and white.
Which is harder, Kyanite or Sapphire?
Sapphire is harder: Mohs 9 against Mohs 5 for Kyanite.
Which is more valuable, Kyanite or Sapphire?
Sapphire is usually the more valuable of the two: a typical collector specimen runs about $5000 against $50 for Kyanite, and premium Sapphire can reach $50000 or more.
