Malachite

Malachite is a green, very common secondary copper mineral with a widely variable habit. Typically it is found as crystalline aggregates or crusts, often banded in appearance, like agates. It is also often found as botryoidal clusters of radiating crystals, and as mammillary aggregates as well.

Malachite is formed by surface weathering process of copper ore and generally not used for copper extraction mow due to insignificant resources and inadequate metallurgical recovery. The crystal system is monoclinic with perfect cleavage, and contact or penetration twinning.T

his opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, ... 

Color: Green

Luster: Silky

Crystal system: Monoclinic crystal system

Chemical formula: Cu₂CO₃(OH)₂

Hardness (Mohs hardness scale): 3.5 – 4

Transparency: Opaque

Twinning: Common as contact or penetration twins on, and. Polysynthetic twinning also present