Identification guide · Minerals
How to Identify Chrysocolla
Chrysocolla is usually blue-green, cyan, and turquoise blue with a vitreous luster and is translucent. It has a Mohs hardness of 2.5. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Its streak is white to pale blue. It is most often confused with Azurite, Malachite, and Fluorite; the tests below separate them.
Chrysocolla identification checklist
| Color | Blue-Green, Cyan, Turquoise Blue | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous | Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner. |
| Transparency | Translucent | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 2.5 | A copper coin (Mohs 3.5) scratches it, but a fingernail does not. |
| Streak | White to pale blue | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | None | |
| Fracture | Conchoidal | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 2.2 | Noticeably light in the hand for its size (specific gravity about 2.2). |
| Crystal system | Orthorhombic |
Extra tests for Chrysocolla
Glass check. Chrysocolla shares a glassy luster and conchoidal fracture with man-made glass. Glass sits near Mohs 5.5 and often contains round gas bubbles, so a hardness test and a hand lens separate them.
Chrysocolla look-alikes and how to tell them apart
Azurite is harder (Mohs 3.5) than Chrysocolla (Mohs 2.5), so Azurite will scratch Chrysocolla and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Chrysocolla vs Azurite →
Malachite is harder (Mohs 4) than Chrysocolla (Mohs 2.5), so Malachite will scratch Chrysocolla and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Chrysocolla vs Malachite →
Fluorite is harder (Mohs 4) than Chrysocolla (Mohs 2.5), so Fluorite will scratch Chrysocolla and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Chrysocolla vs Fluorite →
Both sit near Mohs 2.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Field tips
- Check whether the specimen's color and texture match typical Chrysocolla examples.
- Use hardness, streak, luster, grain size, and locality together; no single trait is enough for every specimen.
Chrysocolla identification FAQ
How can you tell if a rock is Chrysocolla?
Check the color (blue-green, cyan, and turquoise blue), the vitreous luster, a Mohs hardness of 2.5 and a white to pale blue streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Chrysocolla?
Chrysocolla has a Mohs hardness of 2.5. A copper coin (Mohs 3.5) scratches it, but a fingernail does not.
What is the difference between Chrysocolla and Azurite?
Chrysocolla (Mohs 2.5, vitreous luster) and Azurite (Mohs 3.5, vitreous luster) look alike, but hardness, streak and heft usually separate them. See the full Chrysocolla vs Azurite comparison for a side-by-side table.
Is Chrysocolla worth anything?
Entry-level Chrysocolla specimens sell for around $5, typical collector pieces about $25, and premium examples $150 or more depending on size, quality and locality.
What color is Chrysocolla?
Chrysocolla is most often blue-green, cyan, and turquoise blue. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
