Chrysocolla vs Turquoise
| Property | Chrysocolla | Turquoise |
|---|---|---|
| Formula | (Cu,Al)2H2Si2O5(OH)4 · nH2O | CuAl6(PO4)4(OH)8 · 4H2O |
| Crystal System | Orthorhombic | Triclinic |
| Mineral Class | 09 Silicates | 08 Phosphates, Arsenates, and Vanadates |
| Mohs Hardness | 2.0-4.0 | 5.0-6.0 |
| Color | Blue, blue-green, green, turquoise | Sky blue, blue-green, green |
| Luster | Vitreous | Waxy |
| Streak | White to pale blue | White to pale green |
| Transparency | Translucent | Translucent |
| Cleavage | None | None |
| Fracture | Conchoidal | Conchoidal |
Key Differences
- ◆ Turquoise is a phosphate CuAl6(PO4)4(OH)8·4H2O; chrysocolla is a copper phyllosilicate.
- ◆ Turquoise (hardness 5–6) is significantly harder than chrysocolla (hardness 2–4).
- ◆ Turquoise has waxy luster and holds a polish well; chrysocolla has vitreous luster but is too soft for most jewelry.
- ◆ Both display similar blue-green colors due to copper content and are easily confused in rough form.
- ◆ Turquoise has been prized as a gemstone for millennia; chrysocolla is mainly a collector mineral.