Hello All Del-Airs and Interested Guests!
Welcome to the online version of our November 2008 Mineral of the Month:
Malachite is a green mineral with a widely variable habit. Typically it is found as crystalline aggregates or crusts, often banded in appearance, like agates. It is also often found as botryoidal clusters of radiating crystals and as stalactitic aggregates as well. Single crystals and clusters of distinguishable crystals are very uncommon, but when found, they are typically acicular to prismatic. It is found in the oxidized regions of copper deposits. It is also frequently found as a pseudomorph after Azurite crystals. It's chemical properities are as follows:
Crystal Structure: Monoclinic; Mineral Group: Carbonates; Chemical Formula: Cu2[(OH)2ICO3]; Specific Gravity: 4.0; Tenacity: Brittle; Color: Rich Green; Hardness: 3-1/2 to 4; Luster: Adamantine/Vitreous on Crystal Faces. Silky on Fibrous & Botryoidal Habits; Transparency: Translucent to Opaque; Streak: Pale Green; Cleavage: Perfect; Fracture: Irregular/Uneven, Sub-Conchoidal, Fibrous