Malachite
Malachite · Mineral Specimen and Ornamental Stone
Crystal System
Monoclinic; crystal habit is typically botryoidal, fibrous, or massive, frequently forming radiating crystalline aggregates
Mineral Group
Carbonates (specifically a basic copper carbonate)
Chemical Formula
Cu2CO3(OH)2
Formation Process
Supergene processes involving hydrothermal solutions reacting with limestone and other carbonate rocks in the oxidation zones of copper deposits near the Earth's surface.
About This Crystal
The specimen features a vibrant, rich green coloration with characteristic botryoidal to massive habit and a silky to vitreous luster. It exhibits textured, undulating surface formations with varying shades of green, typical of secondary copper minerals.
Physical Characteristics
Color ranges from bright emerald green to dark green; streak is pale green; cleavage is perfect in one direction (though rarely seen in massive forms); fracture is subconchoidal to uneven; specific gravity is approximately 3.8 to 4.0; tenacity is brittle.
Optical Properties
Biaxial (-) with refractive indices around n_alpha = 1.655, n_beta = 1.875, n_gamma = 1.909; strong pleochroism in shades of green; doubly refractive with high birefringence.
Hardness & Durability
Origin Region
Notable sources include the Democratic Republic of Congo, Russia (Ural Mountains), Australia, France, and the southwestern United States (Arizona). It typically forms in the oxidation zone of copper ore deposits.
Hardness & Durability
Mohs hardness of 3.5 to 4. It has low durability and is soft, making it easily scratched by a knife or copper coin. It is sensitive to acids and heat.
Care & Maintenance
Clean gently with a soft cloth and warm soapy water. Avoid ultrasonic cleaners, steam cleaning, acids, harsh chemical detergents, and prolonged exposure to high heat or direct sunlight.
Rarity & Value
Common to uncommon depending on grade and pattern quality; valued as an ornamental stone and mineral specimen. Prices vary widely based on size, polish, and banding definition.
Special Characteristics
Often exhibits chatoyancy in fibrous polished sections and notable banding patterns of alternating light and dark green tones. It reacts with dilute hydrochloric acid by effervescing.
Lore & History
Historically used as a gemstone and pigment throughout ancient Egypt, Greece, and Rome. In modern metaphysical practices, it is regarded as a stone of transformation, balance, and protection, traditionally associated with the heart chakra.