Quartz (silica)
Quartz is one of the most well-known minerals on earth. It occurs in
basically all mineral environments, and is the important
constituent of many rocks. Quartz is also the most varied
of all minerals, occurring in all different forms, habits, and colors. There
are more variety names given to Quartz than any other mineral. Although
the Feldspars as a group are more prevalent than Quartz, as an
individual mineral Quartz is the most common mineral.
Iron Ore
Iron (Fe) is one of the most abundant rock-forming elements, constituting about 5% of the Earth's crust. It is the fourth most abundant element after oxygen, silicon and aluminium, and after aluminium, the most abundant and widely distributed metal. Iron is indispensable to modern civilisation and people have been skilled in its use for more than 3,000 years. However, its use only became widespread in the 14th century, when smelting furnaces (the forerunner of blast furnaces) began to replace forges.
Iron ores are rocks from which metallic iron can be economically extracted. These rocks are usually found in the form of hematite (Fe2O3) or magnetite (Fe3O4). About 98% of world iron ore production is used to make iron in the form of steel. Iron ore provides the foundation for one of Australia’s major export industries.
