Azurite and Malachite
Nevada lode near La Sole
San Juan Co, Utah
This specimen measures 28cm x 14cm
Azurite Cu2CO3(OH)2
Carbonates; basic copper carbonate
Color and Luster: Azure-blue, dark blue; vitreous, dull; streak blue
Hardness: 3.5-4
Cleavage: Good, two directions
Fracture: Conchoidal, brittle
Crystals: Monoclinic; usually in well-formed equidimensional or tabular crystals; also radiating, botryoidal, incrusting, earthy
Polymorph of Malachite
Malachite Cu2CO3(OH)2
Carbonates; basic copper carbonate
Color and Luster: Emerald-green, grass-green, dark green; adamantine, silky, dull; streak light green
Hardness: 3.5-4
Cleavage: Perfect, one direction crosswise
Fracture: Conchoidal, splintery
Crystals: Monoclinic; crystals rare and usually short or long prismatic; also radial, fibrous, botryoidal, stalactitic, incrusting, earthy
Photo by Mary Sutherland
Descriptions taken from
The Audubon Society Field Guide to North American Rocks and Minerals