The term chlorite indicates a series of phyllosilicates having a TOT O structure and different symmetries (monoclinic, orthorhombic, triclinic). The most common species are clinochlore and chamosite.

Crystal System: monoclinic
Habitus: pseudo-hexagonal crystals. Commonly in foliated, fibrous, granular, or earthy aggregates.
Hardness: 2 - 2½
Fracture: uneven
Density: 2.6 - 3.3 g/cm3 
Origin and geological occurrence: chlorite group minerals are typical minerals of low-grade metamorphic rocks. They can be the product of hydrothermal alteration of mafic minerals (e.g., amphibole, pyroxene, biotite). Common in ore veins. It is a detrital component in sedimentary rocks.