Types of Minerals

There are over three thousand different minerals. Based on composition, minerals are classified mainly as metallic and non-metallic minerals. Metallic minerals contain metal in raw form. Metals are hard substances that conduct heat and electricity and have a characteristic lustre or shine. Iron ore, bauxite, manganese ore are some examples. Metallic minerals may be ferrous or non-ferrous. Ferrous minerals like iron ore, manganese and chromite contain iron. A non-ferrous mineral does not contain iron but may contain some other metal such as gold, silver, copper, or lead.

Non-metallic minerals do not contain metals. Limestone, mica, and gypsum are examples of such minerals and coal and petroleum are non-metallic mineral fuels. The process of taking out minerals from rocks buried under the earth’s surface is called mining. Minerals that lie at shallow depths are taken out by removing the surface layer; this is known as open-cast mining. Deep bores, called shafts, must be made to reach mineral deposits that lie at great depths. This is called shaft mining. Petroleum and natural gas occur far below the earth’s surface. Deep wells are bored to take them out, this is called drilling. Minerals that lie near the surface are simply dug out, by the process known as quarrying.