Rock can appear in many different shapes and forms as seen here in this photo of Arches National Park in Utah.
Rock is generally defined as a naturally occurring mixture of minerals. Minerals are the building blocks of rocks. Granite, for example, is a rock that is composed of a mixture of the minerals feldspar, quartz, mica, and hornblende.
The eight most common elements in the Earth’s crust combine to form approximately 98%, by mass, of all of the Earth’s minerals. The two most common elements, silicon and oxygen, alone combine to form the foundation for approximately 96% of all the minerals in the Earth’s crust.
Eight elements make up 98% of the Earth’s crust.
Did You Know?
Over 3,000 minerals have been discovered in the Earth’s crust. Only a small number of them are common, and these are referred to as the rock-forming minerals since they primarily form the rocks of the Earth’s crust. The six most common rock-forming minerals are quartz, feldspar, mica, pyroxene, amphibole, and olivine.
Try This!
Miners at the Tamarack Mine in Minnesota in 1905.
Mining in the U.S.A.
Mining is the process whereby minerals and other valuable resources are extracted from the Earth.
- Click here to see the location of some major mines in the United States.
- Move your cursor over some of the mine symbols in order to see information about the name of the mine, its location and the resource extracted from this mine.
- What is the major resource extracted from the mines in Minnesota? The major resource mined in Minnesota is iron.
- Which state has the most:
- gold mines? Nevada has the most gold mines.
- copper mines? Arizona has the most copper mines.
- In addition to gold and copper, what other resource is extracted in Montana? Cobalt is also mined in Montana.