Azurite
Carbonate · Cu₃(CO₃)₂(OH)₂
Azurite is a deep-blue copper carbonate that forms alongside malachite in weathered copper deposits and often alters to it over time.
What is azurite?
Azurite is a copper carbonate closely related to malachite, distinguished by its intense azure-blue colour. The two often occur together, and azurite can slowly alter into green malachite. It forms glassy blue crystals and earthy masses and was ground into pigment by old master painters.
Properties
- Chemical formula
- Cu₃(CO₃)₂(OH)₂
- Category
- Carbonate
- Hardness (Mohs)
- 3.5–4
- Crystal system
- Monoclinic
- Lustre
- Vitreous
- Streak
- Light blue
- Colour
- Deep azure blue
- Cleavage / fracture
- Good
How to identify azurite
- →Deep, intense blue, sometimes with green malachite alongside.
- →Vitreous lustre on crystals; light-blue streak.
- →Fizzes in acid (a carbonate).
- →Soft, hardness 3.5–4.
Where azurite is found
Fine azurite comes from Morocco, Namibia, Australia (Malbunka) and the southwestern USA (Arizona).
Azurite finds on minShelf
Real specimens catalogued by collectors.
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