Malachite
Malachite · Decorative Stone and Mineral Specimen
Crystal System
Monoclinic; typically forms as botryoidal, fibrous, or stalactitic masses, rarely as distinct prismatic crystals
Mineral Group
Carbonates
Chemical Formula
Cu2CO3(OH)2
Formation Process
Supergene processes in the oxidation zone of copper ore deposits, typically through the reaction of copper-bearing solutions with carbonate rocks
About This Crystal
A polished tumble stone displaying distinct concentric banding in various shades of vibrant green, ranging from pale celadon to deep forest green, with a vitreous to silky luster and opaque transparency
Physical Characteristics
Color includes various shades of green; streak is pale green; cleavage is perfect in one direction; fracture is subconchoidal to uneven; specific gravity is approximately 3.8 to 4.0; tenacity is brittle
Optical Properties
Biaxial negative with high birefringence; pleochroism is distinct in shades of green; refractive index ranges from 1.655 to 1.909
Hardness & Durability
Origin Region
Democratic Republic of Congo, Russia (Ural Mountains), Australia, France, and the USA (Arizona)
Hardness & Durability
Mohs hardness of 3.5 to 4; low toughness and high softness; vulnerable to scratching and sensitive to acids, heat, and ammonia; requires careful wear and maintenance
Care & Maintenance
Clean gently with warm, soapy water and a soft cloth; avoid ultrasonic cleaners, steam, acidic chemicals, and prolonged exposure to direct sunlight or hot water
Rarity & Value
Common to moderately rare depending on the quality of banding and size; value is determined by intricate contrasting patterns, polish quality, and lack of matrix flaws
Special Characteristics
Distinctive concentric banding and concentric eye-like patterns caused by rhythmic precipitation in cavity fillings
Lore & History
Historically used by ancient Egyptians, Greeks, and Romans for amulets, ornaments, and ground into eye shadow; traditionally associated with transformation, emotional healing, and the heart chakra