Rio Tinto, as one of the largest metals and mining companies in the world, posted a market capitalisation of $73.79bn in 2017. A multinational firm, Rio Tinto has its headquarters in Melbourne, Australia and London. Though it supports operations on six continents, the bulk of its activities are centred in Canada and Australia. Rio Tinto devotes the major portion of its operations in the extraction of minerals such as iron ore, uranium, copper, aluminium, diamonds and coal. The company also expends significant resources to refining iron ore and bauxite.