What is a mineral?
A mineral is a naturally occurring, solid, inorganic substance with a definite chemical makeup and an orderly crystal structure. Quartz, salt and diamond are examples.
To be a mineral, a substance must form naturally, be solid at normal temperatures, not be made by living things and have atoms arranged in a repeating pattern. More than 5,000 minerals have been identified. The most common include quartz and feldspar, which make up much of Earth's crust.
Geologists identify minerals by properties such as hardness, color, luster, the color of their powder, called streak, and the way they break. The Mohs scale ranks hardness from 1, talc, to 10, diamond. A fingernail has a hardness of about 2.5 and can scratch gypsum but not calcite.
Minerals in daily life
Minerals are used to make metals, glass, cement, electronics and fertilizers. Gems like rubies, sapphires and emeralds are minerals prized for their beauty. In nutrition, minerals like calcium and iron refer to elements the body needs, which is a different use of the word.
Did You Know?
Ice is technically a mineral, because it is a natural, solid, inorganic substance with a crystal structure.