Azurite is an azure-blue copper mineral, occasionally found as prismatic crystals (rarely faceted), but more usually in massive form intergrown with malachite.

Found specifically in copper-mining areas for example Australia, Chile, Russia, Africa, and China. Stones from Chessy, near Lyons in France are known as chessylite.

Azurite Pictures

Azurite Rough Azurite Crystal

Azurite mine in the Mojave Desert Rough Azurite Mineral

Azurite Properties

Chemical Composition: 
Copper Carbonate (unstable state) - Cu3(CO3)2(OH)2
Classification / Type: 
The unstable state alters to malachite and is generally found in combination as azumalachite.
Colors / Varieties: 
Violet blue commonly associated with malachite; azurite with large percentage of malachite is called azurmalachite. Transparency: Transparent (rare) to Opaque.
Crystal System / Forms: 
Monoclinic System / Prismatic crystals, botryoidal, stalagmatic, massive, banded.
3.5 - 4
Specific Gravity: 
3.70 - 3.90
Cleavage / Fracture: 
Perfect prismatic cleavage observed as schiller but not seen in aggregate / Conchoidal fracture.
Optic Character: 
Anisotropic, D.R.; Biaxial positive
Vitreous to waxy
Refractive Index / Birefringence: 
1.730 - 1.840 / 0.110
Distinct shades of blue (in single crystal)
Surface texture
U.V. Fluorescence: 
Not characteristic
Cause of Color: 
Specific Tests: 
Attacked by hydrochloric acid, light blue streak.
Simulants (with separation tests): 
Azurmalachite (structure), Lapis Lazuli (structure, R.I., S.G.), Chrysocolla (structure, R.I., S.G.)
Geological Occurrence: 
As a secondary mineral in copper deposits. Alters to malachite and formed in association with malachite.
U.S.A. (Arizona), Namibia, France, Romania, Australia, Siberia.
Cuts & Uses: 
Cabochons, beads, carvings.