mineral
Malachite and Azurite on Gossan (Ironstone Matrix)
Cu2CO3(OH)2 (Malachite) on FeO(OH)·nH2O (Limonite/Gossan)
AI-generated identification · may be incorrectHardness: 3.5-4.0 (Malachite); Color: Bright green patterns on dark brown/orange matrix; Luster: Adamantine to vitreous or dull/earthy; Crystal structure: Monoclinic; Specific Gravity: 3.6-4.0.
- Hardness
- 3
- Color
- Bright green patterns on dark brown/orange matrix
- Luster
- Adamantine to vitreous or dull/earthy
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Physical properties
Hardness: 3.5-4.0 (Malachite); Color: Bright green patterns on dark brown/orange matrix; Luster: Adamantine to vitreous or dull/earthy; Crystal structure: Monoclinic; Specific Gravity: 3.6-4.0.
Formation & geological history
Formed through the secondary oxidation of copper ore bodies. Carbonate-rich surface waters react with primary copper sulfide minerals (like chalcopyrite) within the 'gossan' or iron cap of an ore deposit.
Uses & applications
Primarily used as a minor ore of copper, as collector specimens, and historically as a pigment. When solid enough, it is used for lapidary work and jewelry.
Geological facts
Malachite is often used as a 'pathfinder' mineral by geologists to find copper deposits. It was used as a green mineral pigment in paintings until about 1800.
Field identification & locations
Identify in the field by its distinct vibrant green color often associated with rusty brown iron staining. Look for it in the oxidation zones of copper mines. It will fizz slightly when in contact with dilute hydrochloric acid.
