Mining in Minnesota

Lake Superior Agates

What's mined in Minnesota?

Map of minerals mined in Minnesota. Are any minerals mined in the county where you live? Which ones?

Minnesota is the largest producer of iron ore and taconite in the United States. Even though nearly all of the high grade natural iron ore in Minnesota has already been mined, advances in technology have found a use for lower grade iron ore, called taconite. The taconite is crushed, processed into hard, marble-sized pellets, and shipped to steel mills. The taconite pellets are melted in blast furnaces and then blown with oxygen to make steel. Minnesota currently has seven operating taconite plants which make the pellets. About 44 million tons of taconite pellets were shipped from the state in 1996. That's enough to fill over 500,000 railroad cars! In the past, iron ore was mined on three iron ranges - the Cuyuna, Mesabi and Vermilion - and also in Fillmore County in southeastern Minnesota. Today, only the Mesabi Range still has iron ore/taconite mining taking place.

Clay is mined in the Minnesota River Valley. Clay is used in making bricks, porcelain, tiles, and medicines. Companies are currently exploring Minnesota for higher grade kaolin (KAY-a-lin) clay, which is a fine, white clay used to add a glossy look to paper. Today, Georgia is the largest producer of kaolin clay in the United States.

About 11,000 years ago, glaciers covered Minnesota. These glaciers left behind large amounts of sand and gravel. There are sand and gravel mining operations in nearly every county in Minnesota. You may not think of sand and gravel as a valuable resource, but without it concrete could not be made. Highways, roads, bridges and many buildings are made of concrete. Sand is also used along with salt to melt ice on roads and to provide better traction in the snow.

Silica sand is a very fine sand composed of quartz (a white to colorless mineral) and is mined in the southeastern part of Minnesota. It is used to make glass, as a source of silicon, and is used in oil drilling to improve the flow of oil to oil wells.

Granite and limestone are used in the construction of homes, buildings, roads and tombstones. These rocks are often mined in large blocks from a quarry. When granite or limestone is mined this way, it is called dimension stone. Look at the buildings in your town. Are any made with limestone or granite?

Peat is formed by partially decomposing plant material in wet environments, such as bogs or fens, where more plant material is produced than is decomposed. If peat is a plant, how can it be a mineral? Peat is the beginning of the fossilization of the plants. Fossil fuels, such as coal, began as plant material too. Peat is used mainly in the gardening industry, but it is also used for compost, turkey litter, absorbing oil, and fuel. Next time you are in the gardening store, look for peat.

These are the only minerals currently mined in Minnesota. Manganese, copper, nickel, and titanium have also been discovered in the state in minable quantities, but are not of high enough quality under today's prices to mine profitably. Exploration for additional resources, such as gold, platinum, diamonds, zinc, and lead, continues today in Minnesota.