Malachite Gemology

Classification of Malachite

IMA status: Valid – first described prior to 1959 (pre-IMA) – “Grandfathered”
Strunz 8th edition ID: 5/C.01-20
Nickel-Strunz 10th (pending) edition ID: 5.BA.10

B : Carbonates with additional anions, without H2Omalachite
A : With Cu, Co, Ni, Zn, Mg, Mn

Dana 7th edition ID:
Dana 8th edition ID: 16a.3.1.1

3 : (AB)2(XO3)Zq

Hey’s CIM Ref.: 11.2.1

11 : Carbonates
2 : Carbonates of Cu URL:
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Occurrences of Malachite

Geological Setting: It is the most common secondary mineral found in the oxidized zones of copper deposits.

Physical Properties of Malachite

Lustre: Adamantine, Vitreous, Silky, Dull, Earthy
Diaphaneity (Transparency): Transparent, Translucent
Colour: Bright green, with crystals deeper shades of green, even vary dark to nearly black; green to yellowish green in transmitted light.
Streak: Light green
Hardness (Mohs): 3½ – 4
Hardness Data: Measured
Tenacity: Brittle
Cleavage: Perfect
Perfect on {201}, fair on {010}.
Fracture: Irregular/Uneven, Sub-Conchoidal, Fibrous
Density (measured): 3.6 – 4.05 g/cm3
Density (calculated): 4 g/cm3

Crystallography of Malachite

Crystal System: Monoclinic
Class (H-M): 2/m – Prismatic
Cell Parameters: a = 9.48Å, b = 12.03Å, c = 3.21Å
β = 98°
Ratio: a:b:c = 0.788 : 1 : 0.267
Unit Cell Volume: V 362.52 ų (Calculated from Unit Cell)
Z: 4
Morphology: Crystals uncommon, usually short or long prismatic or acicular, parallel to [001]; often grouped in rosettes, sprays, or tufts. Botryoidal to mammilary aggregates of radiating fibrous crystals more common. It may also be massive, compact, and stalactic.
Twinning: Untwinned crystals are extremely rare. Typically twinned on {100}, sometimes as penetration or polysynthetic twinning with the axis parallel to [201].