A mineral is a naturally occuring homogenous substance, which has a more or less definite chemical composition and definite atomic structure. The minerals are usually formed by inorganic processes. They possess a set of constant physical properties. Since the determination of atomic structure and chemical composition requires complex laboratory tests, the more easily recognised physical properties are used in the identification of minerals in the field.
The minerals may be divided into two broad groups: (i) rock-forming minerals, and (ii) ore-forming minerals. Rock-forming minerals are those which are found in abundance in the rocks of Earth’s crust. Ore-forming minerals are those which are of economic value and do not occur in abundance in rocks.
Mineral Groups
There are six basic groups of minerals, based on their chemical composition.