Minerals are classified in several ways. Geologists classify minerals according to their chemical composition and crystalline structure. Some minerals consists of only one element, while other of two or more elements. Generally minerals are classified into two categories Metallic and non- metallic. Metallic minerals are further sub-divided into ferrous (containing iron) and non-ferrous (containing metals other than iron).
1. Metallic Ferrous Minerals:
Iron ore, manganese ore, chromite, pyrite, tungsten, nickel and cobalt.
2. Metallic Non-ferrous Minerals:
Limestone, nitrates, potash, dolomite, mica, gypsum, coal and petroleum.
3. Refractory Minerals:
They are used as heat resistant in furnaces and moulds. They include chromite, magnesite, kyanite, fire clays sillimanite and graphite.
4. Energy Minerals:
Mineral oil, lignite, natural gas and nuclear minerals.
In India, minerals can be divided into four categories as follows:
(i) Minerals of which India’s exportable surplus can dominate the world market; to this category belong iron ore and mica;
(ii) Minerals of which the exportable surplus forms an important factor; these include manganese ore, bauxite, gypsum and others;
(iii) Minerals in which it appears that the country is self-sufficient like coal, sodium salt, glass, sand, phosphates, bauxite etc;
(iv) Minerals for which India has to depend largely or entirely on foreign markets like copper, nickel, petroleum, lead, zinc tin, mercury, platinum, graphite etc.