Chlorite group of minerals

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

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.