Malachite
Malachite (Copper Carbonate Hydroxide) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Monoclinic; typically occurring in botryoidal, fibrous, or stalactitic masses.
Mineral Group
Carbonates
Chemical Formula
Cu2(CO3)(OH)2
Formation Process
Secondary mineral formed by the weathering of copper ores in the oxidation zone of copper deposits, typically through hydrothermal precipitation.
About This Crystal
An opaque, green mineral with a vitreous to silky luster. It is famous for its concentric banding and 'bulls-eye' patterns. In this specimen, it appears as a dark, forest-green mass with a somewhat granular or micro-crystalline surface texture.
Physical Characteristics
Color: Bright to dark green; Streak: Pale green; Fracture: Sub-conchoidal to uneven; Specific Gravity: 3.6-4.0; Luster: Silky to dull/waxy. Non-fluorescent.
Optical Properties
Biaxial negative; Refractive Index: 1.655-1.909; Birefringence: 0.254; Pleochroism: Strong (colorless to yellowish-green to deep green).
Hardness & Durability
Origin Region
Notable sources include Democratic Republic of Congo (Katanga), Russia (Ural Mountains), Namibia (Tsumeb), and Arizona, USA.
Hardness & Durability
Mohs Hardness: 3.5 to 4.0. Brittle toughness; sensitive to heat, acids, and ammonia. Low durability for jewelry rings but suitable for pendants/earrings.
Care & Maintenance
Clean only with warm, soapy water and a soft cloth. Avoid ultrasonic or steam cleaners. Store away from harder gemstones to prevent scratching. Do not use acidic cleaners.
Rarity & Value
Common globally, but high-quality banded specimens are highly valued. Value factors include pattern complexity and size. Often used in carvings and lapidary arts.
Special Characteristics
Notable for its distinct green banding and pseudomorphs (often replacing azurite). Some specimens show chatoyancy in fibrous forms.
Lore & History
Historically used as a pigment (green verditer) and in amulets since 4000 BCE in Ancient Egypt. Symbolically associated with transformation, protection, and the Heart Chakra in traditional crystal lore.