Chlorite is a member of the mica group of minerals (sheet silicates), like biotite and muscovite.

Chlorite is widespread in low grade metamorphic rocks such as slate and schist, in sedimentary rocks, and as a weathering product of any rocks that are low in silica (especially igneous rocks).

Chemical composition - (Fe, Mg, Al) 6(Si, Al) 4O 10(OH) 8
Hardness - 2-2.5
Specific gravity - 2.6-3.4
Transparency - Translucent to transparent
Colour - Generally green (various shades)
Streak - Pale green
Lustre - Vitreous, pearly
Cleavage/fracture - Perfect / uneven
Crystal habit/mode of occurrence - Tabular (rarely large individual barrel or tabular crystals with a hexagonal outline) / fine-grained, scaly or massive aggregates of small scales