Crystal Brochantite

Chemical Formula

CuSO₄(OH)₆

Composition

Basic copper sulfate

Color

Bright green to dark green

Streak

Pale green

Hardness

3.5 - 4

Crystal System

Monoclinic

Crystal Forms 
and Aggregates

Very rarely in visible crystals, which are prismatic and tabular. Most often acicular, radiating, earthy, grainy, encrusting, as fibrous masses, as dense bundles of acicular crystals, and as cotton-like, radiatingmasses. Sometimes as tiny twinned crystals that appear orthorhombic with rounded corners. Occasionally forms a pseudomorph after Azurite and Malachite, assume the crystal shape of those minerals.
 

Transparency

Transparent to opaque

Specific Gravity

4

Luster

Vitreous to silky

Cleavage

1,1 - pinacoidal

Fracture

Conchoidal, uneven, splintery

Tenacity

Brittle

In Group

Sulfates; Hydrous Sulfates

Striking Features

Intense green color, crystal habits, and mode of occurrence

Environment

Brochantite is a secondary copper mineral formed in the oxidation zone of copper deposits.

Rock Type

Sedimentary, Metamorphic

Popularity (1-4)

3

Prevalence (1-3)

2

Demand (1-3)

2