Minerals are important in many industries. Minerals used in gems are usually very hard. These are then set in varying styles of jewellery. Iron and copper are metals used in almost everything. Copper is present in everything from coins to pipes and electricity wires. Silicon, obtained from the mineral quartz, is the base of the computer industry. Aluminium, obtained from bauxite ore, and its alloys are used in aeroplanes due to their lightweight. Aluminium is also used in kitchen cookware.