Mineral Type - Azurite

A secondary copper mineral frequently found in the oxidized zones of Cu-bearing ore deposits.
Azurite is typically found as tabular to prismatic crystals of a deep "azure blue" color with splendent vitreous faces. There are over 45 well-known forms, and over 100 forms have been described. Azurite is often pseudomorphed to Malachite, and the two are very frequently found together. Azurite may be confused with (the very rare) Mrázekite.

Name

From the ancient Persian lazhward, meaning "blue", in allusion to the color. Name changed to azurite in 1824 by Francois Sulpice Beudant.

Physical Properties

Lustre: Vitreous
Transparency: Transparent, Translucent
Colour: Azure blue, blue, light blue, or dark blue; light blue in transmitted light
Streak: Light blue
Hardness: 3½ - 4 on Mohs scale
Tenacity: Brittle
Cleavage: Perfect. Perfect on {011}; on {100} fair; on {110} in traces.
Parting: None
Fracture: Conchoidal
Density: 3.77 g/cm3 (Measured) 3.834 g/cm3 (Calculated)

Chemical Properties

Formula: Cu3(CO3)2(OH)2
Elements lised: C, Cu, H, O

Crystallography

Crystal System: Monoclinic
Class (H-M): 2/m - Prismatic
Space Group: P21/b
Morphology: Tabular {001}, less common {102} or {102}; prismatic [001] or [010]; sometimes equant or even rhombohedral; faces may be wavy with striations on {001} parallel to "a", on {100} parallel to "b." May also be massive, stalactic, or botryoidal.
Twinning: Rare, across {101}, {102} or {001}.

Synonyms

Armenite (of Delamétherie), Azure Copper Ore, Azurite (of Beudant), Blue Carbonate of Copper, Blue Malachite, Chessy copper, Chessylite, Lasur, and Lasurite (of Haidinger)

Varieties

Kupferblau, and Zincazurite