Chemical composition -- A hydrated copper carbonate.
Color -- Light to dark shades of green. Often banded or with swirled or bull's-eye patterns.
Optics -- R.I. 1.65-1.91.
Durability -- Hardness 3.5-4.5. Moderately brittle, but usable in jewelry.
Crystal structure -- Monoclinic, often massive. Crystals too small to facet.
Specific Gravity -- 4.05.
Sources -- Malachite occurs in huge sizes and has been
widely used for ornamental and architectural items. Zaire is a primary source.