Chlorite
Real mineral · common · (Mg,Fe)₃(Si,Al)₄O₁₀(OH)₂·(Mg,Fe)₃(OH)₆
A phyllosilicate group forming during low-grade metamorphism and hydrothermal alteration. Its green colour results from iron and magnesium content. Commonly found coating fractures and replacing ferromagnesian minerals in altered igneous rocks.
Identity
- Formula
- (Mg,Fe)₃(Si,Al)₄O₁₀(OH)₂·(Mg,Fe)₃(OH)₆
- Chemical class
- silicate
Crystallography
- Crystal system
- monoclinic
- Habits
- foliated, massive, granular
- Fracture
- uneven
Physical properties
- Mohs hardness
- 2.5
- Density
- 2.65 g/cm³
- Luster
- vitreous, pearly
- Colors
- green, dark green, olive green, black, white
- Streak
- white to pale green
- Transparency
- translucent, opaque
Geology
- Origins
- metamorphic, hydrothermal
- Host rocks
- schist, phyllite, basalt
- Associated minerals
- Quartz, Garnet, Mica, Epidote
- Geography
- worldwide
Classification
- Rarity
- common
- Gem quality
- No
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