Malachite
| Malachite | |
|---|---|
Malachite frae the Congo
|
|
| General | |
| Category | Carbonate mineral |
| Formula (repeating unit) |
Cu2CO3(OH)2 |
| Strunz classification | 05.BA.10 |
| Identification | |
| Formula mass | 221.1 g/mol |
| Color | Bricht green, dark green, blackish green, commonly banded in masses; green tae yellaeish green in transmittit licht |
| Crystal habit | Massive, botryoidal, stalactitic, crystals are acicular tae tabular prismatic |
| Crystal seestem | Monoclinic—prismatic H-M Symbol (2/m) Space group P21/a |
| 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 hairdness | 3.5–4.0 |
| Luster | Adamantine tae vitreous; silky if fibrous; dull tae yirdy if massive |
| Streak | licht green |
| Diaphaneity | Translucent tae opaque |
| Specific 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] Typical malachite is laminatit an whether or nae microbes intervene in its furmation is unkent.
