RocksdayChrysocolla vs Malachite
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 vivid green copper carbonate with bold light-and-dark banding. It forms where copper deposits weather near the surface.
Photo: JJ Harrison (https://www.jjharrison.com.au/), CC BY-SA 3.0
Quick tests
- Acid (vinegar or dilute HCl): Malachite fizzes; Chrysocolla doesn't.
- Streak (rub on unglazed porcelain): Chrysocolla leaves a pale blue to white streak; Malachite leaves light green.
- Heft: Malachite feels noticeably heavier for its size (specific gravity 3.6–4.05 vs 1.9–2.4).
Key differences
- Malachite is green, banded and fizzes in acid.
Side by side
| Property | Chrysocolla | Malachite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 2.5–3.5 | 3.5–4 |
| Luster | Vitreous to earthy | Silky to dull |
| Streak | Pale blue to white | Light green |
| Colors | Blue, Green | Green |
| Crystal system | Amorphous to cryptocrystalline | Monoclinic |
| Specific gravity | 1.9–2.4 | 3.6–4.05 |
| Formula | (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O | Cu₂CO₃(OH)₂ |
| Found in | Arizona; Peru | Katanga, DR Congo; Ural Mountains, Russia |
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 malachite
- Bright green with concentric light/dark bands.
- Fizzes in acid.
- Feels heavy for a stone.
- Light green streak.
Crystal system: Monoclinic
Full Malachite guide →More comparisons
Could you tell them apart from a blurry close-up?
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