Rio Tinto searches for and extracts a variety of minerals worldwide, with the heaviest concentrations in North America and Australia. Iron ore is the dominant commodity, with significantly lesser contributions from aluminium, copper, diamonds, gold, and industrial minerals. The 1995 merger of RTZ and CRA, via a dual-listed structure, created the present-day company. The two operate as a single business entity. Shareholders in each company have equivalent economic and voting rights.