Turquoise
| Colour | Blue, Green |
|---|---|
| Mohs hardness | 5–6 |
| Lustre | Waxy to subvitreous |
| Streak | Bluish white |
| Crystal system | Triclinic |
| Transparency | Opaque |
| Cleavage | Perfect on {001}, good on {010}, but cleavage rarely seen |
| Fracture | Conchoidal |
| Specific gravity | 2.6–2.9 |
What is Turquoise?
Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl6(PO4)4(OH)8·4H2O. It is rare and valuable in finer grades and has been prized as a gemstone for millennia due to its hue.
How to identify Turquoise
- Lustre: Waxy to subvitreous.
- Hardness: Mohs 5–6 — about as hard as a steel knife.
- Streak: Bluish white.
- Habit: Triclinic crystal system.
Turquoise in different forms
Stones often confused with Turquoise
Frequently asked questions
How hard is Turquoise?
Turquoise is Mohs 5–6 on the hardness scale.
What colour is Turquoise?
Turquoise is typically blue, green (Turquoise, blue, blue-green, green).