Commercially, the slates are defined as layered stone that can be split into slices of thickness ranging from 8 to 14 mm. Slates/Scihists are generally fine grained and occur in various shades of grey to steel grey, greenish grey, dark grey, purplish grey, brownish, ash and sometimes with other pleasing colours. Slates/Schists have varying degree of hardness. The harder ones are being sometimes used for flooring.
These are low cost decorative stones having wide applications after cutting for use in interior as well as exterior decorations.
Schist and slate stones are argillaceous rocks having different grades of metamorphism. Certain planes of easy split called 'schistosity', are developed in these rocks due to metamorphism, which make these rocks suitable for decorative use. The slates/schists having good and even cleavages are valued much. The planes of cleavage are related solely to the direction of pressure to which the material was subjected and not to the bedding plane.
Micaceous and chlorite slates/schists are generally of good quality.
These are used for roofing, paving, shelves and flooring purposes in the rural areas in and around the places where it is mined. Now a days slates/schists are cut in to tiles and used for wall claddings. Slates are also used for making school slates.