The slow but persistent action of a number of geo-chemical processes and biological activity has given rise to large deposits of different minerals in different parts of the world.
In terms of total amount of metal content as known till 1975 A.D., Iron minerals like Haematite, Magnetite, and Siderite etc. are the most abundant minerals. In the form of these minerals a huge quantity of iron, about 109,000 million metric tons is available to us.
Iron is followed by Aluminium which occurs as Bauxite, Manganese which occurs as Pyrolusite, Chromium as Chromite, Copper as Chalcopyrite, Zinc as Sphalerite, and Lead as Galena in order of decreasing abundance. In global reserves of metals as known till 1975 A.D., their major mineral source and important producer countries are summarized. These estimates differ from person to person and from time to time as new deposits are continuously being discovered.