Malachite

Hardness: 3.5-4.0 on Mohs scale. Color: Bright green, dark green, or blackish green with characteristic concentric bands. Luster: Adamantine to vitreous or silky when raw, glossy when polished. Crystal Structure: Monoclinic. Cleavage: Perfect in one direction, though rarely seen in massive or tumbled forms. Specific Gravity: 3.6-4.0.

Formed as a secondary mineral in the oxidation zone of copper ore deposits. Hydrothermal solutions carrying dissolved copper react with carbonate rocks or carbonated waters, precipitating malachite in botryoidal, fibrous, or stalactitic habits.

Widely used as an ornamental stone, for lapidary carvings, beads, and cabochons in jewelry. Historically ground down as a green pigment (verditer) for paint and used as a copper ore.

Malachite was used as a green eye makeup in ancient Egypt and was mined in the Sinai peninsula as early as 4000 BCE. Its distinct circular, concentric banding is often referred to as 'peacock' or 'bullseye' patterns.

Identified by its distinctive vibrant green concentric banding, high density due to copper content, and reaction (effervescence) with cold dilute hydrochloric acid. Commonly found in Russia (Urals), Democratic Republic of the Congo, Zambia, Namibia, and Arizona, USA. Collectors should be careful as polished specimens can react with moisture or acid, and malachite dust is toxic if inhaled during cutting.