The iron oxide mineral, magnetite, is mined from flintlike rock that is high in silica and referred to as Precambrian sedimentary rock. Its chemical formula is Fe3O4 with 72 percent iron. Magnetite is a natural resource of industrial steel and iron. Due to its use in industry, magnetite iron ores have become a major export for countries that have the mineral in great abundance. North America, in particular, is very dependent on magnetite imports because natural resources in North America are growing scarce.
Iron ore, including magnetite, is one of Australia's largest exports. According to the Australian government, magnetite deposits are predominantly in Queensland and an area known as the Northern Territory. Australian magnetite ore mining sites include Savage River in Tasmania, the Southdown Magnetite Project in Albany, the Sino iron project at Cape Weston and the Karara iron ore project in the Blue Hills. As of February 2011, a magnetite plant was constructed at the Ernest Henry mine in Queensland.
North American magnetite mining sites are found in both the United States and eastern Canada in banded rock formations. The most profitable magnetite iron ore deposits in the United States can be found at Minnesota's Mesabi Iron Range, Michigan's Lake Erie, lower Lake Michigan and the New York Adirondack Mountains. Smaller U.S. deposits are located in North Carolina, Pennsylvania, Oregon, Colorado, New Mexico, Utah, Virginia and New Jersey. In Canada, magnetite deposits are available along the St. Lawrence River in Sept-Iles, Quebec.
Brazil is one of the largest exporters of magnetite in the world. Like Australia, Brazil's magnetite sources are predominantly sold to Asia. The state of Minas Gerais has a 4.5-kilometer stretch of mining land referred to as the Iron Quadrangle with magnetite mining sites in the districts of Itabira, Santa Barbara, Ouro Preto, Mariana and Nova Lima. Unlike United States' mines, magnetite ores can be found along the Iron Quadrangle in perfect formation.
India is a rich source of a magnetite ore in southeast Asia. Specifically, the mineral is mined in the mountains of Andhra Pradesh, Karnataka and Goa. According to Indian information source, MBendi, Karnataka reserves have the highest grade minerals with over 65 percent of iron in deposits. Goa and Andhra Pradesh reserves are considered to be medium grade with iron compositions in magnetite ores ranging from 62 to 65 percent. Minerals are exported to Far East countries of South Korea, Japan and China.