BAUXITE - Arkansas, USA

BAUXITE

Bauxite, Saline County, Arkansas, USA

Bauxite is a sedimentary rock with a relatively high aluminium content and is the world's main source of aluminium. It is formed by the weathering of rocks and the concentration of aluminium compounds. It contains other minerals, including iron oxides which can give it a reddish colour.

Arkansas was originally the source of almost all of the aluminium used in the USA but the mines were finally closed in the 1980s. The town of Bauxite in Arkansas was named after this rock.

This specimen is an unpolished slice of bauxite and is a classic example of the rock from this locality. It is composed of orbicular nodules in matrix which is known as a pisolitic structure.