sedimentary

Bauxite

Bauxite (mixture of Hydrous Aluminum Oxides)

AI-generated identification · may be incorrect

Hardness: 1-3 Mohs; Color: reddish-brown, tan, or gray; Luster: earthy/dull; Structure: pisolitic (pea-like) or massive; Specific Gravity: 2.0-2.5

Hardness: 1-3 Mohs
Color: reddish-brown, tan, or gray
Luster: earthy/dull

Identified March 24, 2026More sedimentary →

Explore Bauxite in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 1-3 Mohs; Color: reddish-brown, tan, or gray; Luster: earthy/dull; Structure: pisolitic (pea-like) or massive; Specific Gravity: 2.0-2.5

Formation & geological history

Formed through the intense chemical weathering of rocks in hot tropical or subtropical climates, which leaches away silica and results in an accumulation of aluminum oxides. Most deposits date from the Tertiary period through to the present.

Uses & applications

Primary ore of aluminum; also used in the production of abrasives, refractories, chemicals, and cement.

Geological facts

Bauxite is not a single mineral but a rock composed primarily of gibbsite, boehmite, and diaspore. It was first discovered in 1821 near the village of Les Baux in southern France.

Field identification & locations

Identify by its reddish color and 'ooolitic' or 'pisolitic' circular grain textures. Commonly found in Australia, Guinea, Brazil, and Jamaica. Collectors should look for distinct pea-sized structures.