Malachite
Malachite · Semi-Precious Gemstone and Decorative Stone
Crystal System
Monoclinic; typically forms in botryoidal, fibrous, or stalactitic masses
Mineral Group
Carbonates
Chemical Formula
Cu2CO3(OH)2
Formation Process
Supergene secondary formation through the alteration of copper sulfide ores, occurring near the Earth's surface under low-temperature hydrothermal conditions
About This Crystal
A polished tumbled stone exhibiting distinctive bands of alternating light and dark green colors, opaque transparency, and a vitreous to silky luster
Physical Characteristics
Light green streak, perfect cleavage in one direction, uneven to sub-conchoidal fracture, specific gravity of 3.6 to 4.0, brittle tenacity, and non-magnetic
Optical Properties
Biaxial (-) with high birefringence and strong pleochroism in shades of green
Hardness & Durability
Origin Region
Democratic Republic of Congo, Russia, Australia, and Arizona, USA; forms in the oxidation zone of copper ore deposits
Hardness & Durability
Mohs hardness of 3.5 to 4; poor toughness and low durability, highly sensitive to acids, and requires careful handling in jewelry
Care & Maintenance
Clean gently with warm, soapy water; avoid ultrasonic and steam cleaners, harsh chemicals, and prolonged exposure to direct sunlight or acids
Rarity & Value
Common to uncommon depending on the quality of banding; value is determined by color saturation, pattern complexity, and size, with tumbled stones being quite affordable
Special Characteristics
Distinctive concentric banding and chatoyant fibrous effects when cut properly, though not visible as a strong cat's-eye in this tumbled specimen
Lore & History
Historically used by ancient Egyptians for jewelry, amulets, and powdered eye makeup; associated with transformation, emotional balance, and the heart chakra in metaphysical traditions