What does California mine?

* Gold. California is the leading gold-producing state in the United States, and has been since the 1849 Gold Rush. The majority of gold produced in California comes from the Mother Lode, a 120-mile-long gold-bearing quartz vein that runs from Mariposa County to El Dorado County.

* Sand and gravel. Sand and gravel are used in construction, paving, and other industrial applications. California is a major producer of both sand and gravel, and has some of the largest deposits of these materials in the country.

* Cement. Cement is used to make concrete, which is a key material in construction. California is the second-largest cement-producing state in the United States, and has several large cement plants located throughout the state.

* Clays. Clays are used in a variety of applications, including ceramics, pottery, and construction. California is a major producer of clays, and has some of the largest deposits of these materials in the country.

* Diatomite. Diatomite is a sedimentary rock that is composed of the fossilized remains of diatoms, a type of algae. Diatomite is used as a filter aid, in polishing compounds, and as an absorbent. California is the leading diatomite-producing state in the United States, and has several large deposits of this material located in the state.