Malachite
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| Malachite | |
|---|---|
 Malachite frae the Congo | |
| General | |
| Category | Carbonate mineral |
| Formula (repeatin unit) | Cu2CO3(OH)2 |
| Strunz clessification | 05.BA.10 |
| Creestal seestem | Monoclinic—prismatic H-M Symbol (2/m) Space group P21/a |
| Identification | |
| Formula mass | 221.1 g/mol |
| Colour | Bricht green, dark green, blackish green, commonly banded in masses; green tae yellaeish green in transmittit licht |
| Creestal habit | Massive, botryoidal, stalactitic, crystals are acicular tae tabular prismatic |
| Twinnin | Common as contact or penetration twins on {100} an {201}. Polysynthetic twinnin an aa present. |
| Cleavage | Perfect on {201} fair on {010} |
| Fractur | Subconchoidal tae uneven |
| Mohs scale haurdness | 3.5–4.0 |
| Skinkle | Adamantine tae vitreous; silky if fibrous; dull tae yirdy if massive |
| Streak | licht green |
| Diaphaneity | Translucent tae opaque |
| Speceefic gravity | 3.6–4 |
| Optical properties | Biaxial (–) |
| Refractive index | nα = 1.655 nβ = 1.875 nγ = 1.909 |
| Birefringence | δ = 0.254 |
| References | [1][2][3] |
Malachite is a copper carbonate hydroxide mineral, wi the formula Cu2CO3(OH)2. This opaque, green bandit mineral crystallizes in the monoclinic crystal seestem, an maist eften furms botryoidal, fibrous, or stalagmitic masses, in fracturs an spaces, deep unnergrund, whaur the watter table an hydrothermal fluids provide the means for chemical precipitation. Individual crystals are rare but dae occur as slender tae acicular prisms. Pseudomorphs efter mair tabular or blocky azurite crystals an aa occur.[3] teepical malachite is laminatit an whether or nae microbes intervene in its furmation is unkent.