The chlorite group includes a number of minerals, which have similar physical properties. They are sheet silicate (phyllosilicate) minerals, which were formed during early metamorphism. They have an oily/soapy feel and perfect cleavage. They are found in all sedimentary, igneous, and metamorphic rocks. The important mineral of this group is ”Chlorite”.
Chlorite Minerals: (Mg,Fe) 3(Si,Al) 4O 10(OH) 2·(Mg,Fe) 3(OH) 6
Physical Properties of Chlorite:
- Crystal System: Chlorite minerals have a monoclinic crystal system.
- Cleavage: Chlorite mineral has perfect basal cleavage.
- Hardness: Chlorites are very soft minerals that have 2-2.5 hardness on Moh’s scale.
- Sp.gr: Specific gravity of the chlorite group of minerals is 2.6- 3.3.
- Luster: Chlorites have a vitreous lustre, resinous or dull luster.
- Colour: Chlorite minerals have a green colour with various shades.
- Habit: They are usually habited in foliated mass.
Occurrence of Chlorite Minerals:
Chlorite is a common mineral found in low-grade metamorphic rocks, such as chlorite-schists. In igneous rocks, it occurs as an alteration product of pyroxenes, amphibole, and biotite.
Minerals Species of Chlorite Group:
Uses of Chlorites:
- There are very few industrial uses of chlorite minerals.
- As chlorites do not have definite physical properties, which do not make them suited for a particular use. Moreover, chlorites are mixed with other minerals, which makes its mining expensive. Therefore, it is not mined for making it useable for any purpose.
- Chlorites are taken as a constituent of clay and used as filler.
- Chlorite is found abundantly in many types of crushed stone, therefore, the mere use of chlorite is as a filler material.