Chrysocolla
Chrysocolla (IMA approved) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Orthorhombic (rarely crystalline); typically occurs in massive, botryoidal, or earthy habits
Mineral Group
Silicates; Subgroup: Phyllosilicates
Chemical Formula
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (hydrated copper phyllosilicate)
Formation Process
Secondary mineral formed in the oxidation zones of copper ore bodies by hydrothermal or meteoric water
About This Crystal
Opaque, vibrant blue-green to cyan gemstone with a dull to vitreous luster; often intermixed with quartz, malachite, or darker copper oxides
Physical Characteristics
Color: Cyan to green; Streak: White to pale blue; Cleavage: None; Fracture: Conchordal to irregular; Specific Gravity: 2.0-2.4; Non-fluorescent
Optical Properties
Refractive Index: 1.575-1.635; Biaxial negative; Often cryptocrystalline (appearing isotropic under polariscope)
Hardness & Durability
Origin Region
Arizona (USA), Chile, Peru, Democratic Republic of the Congo, and Israel (Eilat Stone)
Hardness & Durability
Mohs Hardness: 2.0-4.0 (up to 7.0 if silicified); Poor toughness; very brittle and sensitive to pressure
Care & Maintenance
Avoid ultrasonic cleaners and steam; clean with damp cloth; keep away from acids, solvents, and prolonged sunlight
Rarity & Value
Common globally but high-quality 'Gem Silica' (quartz-infused) is rare and valuable; mid-range for decorative specimens
Special Characteristics
Often forms pseudomorphs after other minerals; exhibits a high copper content giving it striking coloration
Lore & History
Known as the Stone of Communication; historically used by American Indians for strengthening body resistance and emotional calming