Comparison · Metamorphic Rocks vs Semi-Precious Stones
Blueschist vs Turquoise
Blueschist and Turquoise are easy to confuse. Both sit near Mohs 5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Blueschist and Turquoise
- Both sit near Mohs 5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Blueschist leaves a variable; usually pale gray streak on unglazed porcelain, Turquoise leaves white to pale green.
- They overlap in blue and green, but Blueschist also comes in gray and black.
Blueschist vs Turquoise properties
| Property | Blueschist | Turquoise |
|---|---|---|
| Type | Metamorphic Rocks | Semi-Precious Stones |
| Mohs hardness | 5.5 | 6 |
| Luster | silky | waxy |
| Streak | Variable; usually pale gray | White to pale green |
| Transparency | opaque | opaque |
| Specific gravity | 3.1 | 2.76 |
| Crystal system | varies | triclinic |
| Common colors | Blue, Blue gray, Gray, Green, Black | Blue, Blue-Green, Green |
| Rarity | uncommon | uncommon |
| Typical specimen value | $5–$150+ | $20–$1000+ |
Which is more valuable?
Turquoise is usually the more valuable of the two: a typical collector specimen runs about $100 against $30 for Blueschist, and premium Turquoise can reach $1000 or more.
About Blueschist
Blueschist is a blue to blue-gray metamorphic rock linked to subduction zones. Its color often comes from blue amphibole minerals such as glaucophane.
About Turquoise
Turquoise is a blue-green phosphate mineral prized for thousands of years. Persian turquoise is considered the finest quality.
Blueschist vs Turquoise FAQ
Is Blueschist the same as Turquoise?
No. Blueschist is a metamorphic rock while Turquoise is a semi-precious stone. Both sit near Mohs 5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Blueschist from Turquoise?
Both sit near Mohs 5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Blueschist leaves a variable; usually pale gray streak on unglazed porcelain, Turquoise leaves white to pale green. They overlap in blue and green, but Blueschist also comes in gray and black.
Which is harder, Blueschist or Turquoise?
Turquoise is harder: Mohs 6 against Mohs 5.5 for Blueschist.
Which is more valuable, Blueschist or Turquoise?
Turquoise is usually the more valuable of the two: a typical collector specimen runs about $100 against $30 for Blueschist, and premium Turquoise can reach $1000 or more.
