Azurite vs Malachite
Azurite and Malachite are genuine alternatives to one another — a choice somebody actually makes — and differ on 3 measured properties, density most clearly.
Azurite vs Malachite
Azurite
Cu3(CO3)2(OH)2
The blue copper carbonate that slowly becomes the green one — which is why so many old skies have turned to foliage.
Malachite
Cu2(CO3)(OH)2
A green copper carbonate — an ore, the oldest green pigment, and a banded ornamental stone, all from the same weathered copper deposit.
| Property | Azurite | Malachite |
|---|---|---|
| Crystal system Categorical values can be listed side by side but not ordered or subtracted. | monoclinic | monoclinic |
| Density | 3.7–3.9 g/cm³ | 3.6–4.05 g/cm³ higher |
| Lustre Categorical values can be listed side by side but not ordered or subtracted. | vitreous | silky to dull, adamantine in crystals |
| Mohs hardness Mohs hardness is an ordinal scale: values can be ranked, but differences and ratios between them are not meaningful. | 3.5–4 | 3.5–4 |
| Streak Categorical values can be listed side by side but not ordered or subtracted. | light blue | pale green |