RocksdayAzurite vs Sodalite
How to tell them apart
An intensely deep blue copper carbonate. Over time it slowly converts to green malachite, and the two are often found together.
Photo: Ivar Leidus, CC BY-SA 4.0
A royal-blue feldspathoid mineral, usually massive with white veins, and a popular tumbled stone.
Photo: Ra'ike (see also: de:Benutzer:Ra'ike), CC BY-SA 3.0
Quick tests
- Hardness: Sodalite is clearly harder: Mohs 5.5–6 versus 3.5–4.
- Acid (vinegar or dilute HCl): Azurite fizzes; Sodalite doesn't.
- Streak (rub on unglazed porcelain): Azurite leaves a light blue streak; Sodalite leaves white.
- Heft: Azurite feels noticeably heavier for its size (specific gravity 3.77–3.78 vs 2.27–2.33).
Key differences
- Sodalite is harder, has white veins and doesn't fizz.
- Azurite is softer and fizzes in acid.
Side by side
| Property | Azurite | Sodalite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 3.5–4 | 5.5–6 |
| Luster | Vitreous | Vitreous to greasy |
| Streak | Light blue | White |
| Colors | Blue | Blue, White |
| Crystal system | Monoclinic | Cubic |
| Specific gravity | 3.77–3.78 | 2.27–2.33 |
| Formula | Cu₃(CO₃)₂(OH)₂ | Na₈(Al₆Si₆O₂₄)Cl₂ |
| Found in | Bisbee, Arizona; Tsumeb, Namibia | Bancroft, Ontario; Bahia, Brazil |
Properties that are the same for both are grayed out.
How to identify azurite
- Deep 'azure' blue, often with green malachite.
- Fizzes in acid.
- Soft — a knife scratches it.
- Light blue streak.
Crystal system: Monoclinic
Full Azurite guide →How to identify sodalite
- Royal blue with white veins or patches.
- Glows orange under longwave UV light.
- Hardness about 6.
- Light for a blue stone.
Crystal system: Cubic
Full Sodalite guide →More comparisons
Could you tell them apart from a blurry close-up?
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