RocksdayChrysocolla vs Turquoise
How to tell them apart
A blue-green hydrated copper silicate that forms crusts and fillings where copper deposits weather.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
A copper aluminum phosphate prized for its sky-blue to green color, often webbed with brown or black host rock ('matrix').
Photo: Robert M. Lavinsky, CC BY-SA 3.0
Quick tests
- Hardness: Turquoise is clearly harder: Mohs 5–6 versus 2.5–3.5.
- Streak (rub on unglazed porcelain): Chrysocolla leaves a pale blue to white streak; Turquoise leaves white to greenish.
Key differences
- Turquoise is harder and heavier.
Side by side
| Property | Chrysocolla | Turquoise |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 2.5–3.5 | 5–6 |
| Luster | Vitreous to earthy | Waxy to dull |
| Streak | Pale blue to white | White to greenish |
| Colors | Blue, Green | Blue, Green |
| Crystal system | Amorphous to cryptocrystalline | Triclinic |
| Specific gravity | 1.9–2.4 | 2.6–2.9 |
| Formula | (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O | CuAl₆(PO₄)₄(OH)₈·4H₂O |
| Found in | Arizona; Peru | Arizona; Nevada |
Properties that are the same for both are grayed out.
How to identify chrysocolla
- Vivid blue to blue-green, often mixed with malachite or quartz.
- Soft and light; may stick slightly to the tongue.
- No crystals — crusts, veins and botryoidal masses.
Crystal system: Amorphous to cryptocrystalline
Full Chrysocolla guide →How to identify turquoise
- Opaque sky blue to green with a waxy look.
- Often veined with brown or black matrix.
- Never forms visible crystals — always massive nuggets or veins.
- Porous: it can darken when oiled.
Crystal system: Triclinic
Full Turquoise guide →More comparisons
Could you tell them apart from a blurry close-up?
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