Chemical Classification of Rocks

The Chemical Classification of Rocks are,

(a) Siliceous rocks : These rocks have silica (and, quartz and flint) as their principal constituent and are very hard and durable, unaffected by weathering. Chief types of siliceous rocks are Granites, Traps, Quartzite and Sandstones.

(b) Calcareous rocks : Calcium carbonate or lime is the main constituent of these rocks. Crystalline and compact types are hard and durable. Clay is very often found mixed in such rocks. Marbles and limestone are calcareous rocks.

(c) Argillaceous rocks : Rocks of the clayey types which are more or less composed of alumina mixed with small quantities of other minerals. Slates and laterites belong to this group.

Chemical Classification of Rocks – Also see geological classification of rocks