Crystal Azurite

Chemical Formula

Cu₃(CO₃)₂(OH)₂

Composition

Basic copper carbonate

Color

Blue to very dark blue

Streak

Light blue

Hardness

3.5 - 4

Crystal System

Monoclinic

Crystal Forms 
and Aggregates

Usually in small crystals, which are in prismatic, tabular, or equidimensional form. Crystals are sometime striated. Other forms are massive, crusty, radiating, fibrous, earthy, columnar, stalactitic, as thin needles, and in ball-like aggregates. Also occurs in dense groups of tabular or prismatic crystals. Azurite may also form as a pseudomorph over other minerals, retaining the original crystal shape of the mineral that it formed a pseudomorph over.
 

Transparency

Opaque. Rarely translucent.

Specific Gravity

3.7 - 3.9

Luster

Vitreous or dull

Cleavage

2,1 ; 3,2

Fracture

Conchoidal or splintery

Tenacity

Brittle

Other ID Marks

Complex Tests

Effervesces in hydrochloric acid and soluble in ammonia.

In Group

Carbonates

Striking Features

Deep blue color, blue streak, and common association with green Malachite

Environment

As a secondary mineral in the oxidation zone of copper deposits.

Rock Type

Sedimentary, Metamorphic

Popularity (1-4)

2

Prevalence (1-3)

2

Demand (1-3)

1