sedimentary

Bauxite

AlOx(OH)3-2x (mixture of Gibbsite, Boehmite, and Diaspore)

AI-generated identification · may be incorrect

Hardness: 1-3 Mohs; Color: reddish-brown, white, tan, yellow; Luster: dull to earthy; Crystal Structure: amorphous or microcrystalline; Specific Gravity: 2.0-2.5; Pisolitic (pea-sized) texture.

Hardness: 1-3 Mohs
Color: reddish-brown, white, tan, yellow
Luster: dull to earthy

Identified June 11, 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, white, tan, yellow; Luster: dull to earthy; Crystal Structure: amorphous or microcrystalline; Specific Gravity: 2.0-2.5; Pisolitic (pea-sized) texture.

Formation & geological history

Formed by the intense chemical weathering of rocks (like granite or basalt) in tropical or subtropical climates through a process called lateritization, which leaches away silica leaving aluminum oxides.

Uses & applications

Primary ore of aluminum; used in the manufacture of aluminum metal, abrasives, refractories, and chemicals.

Geological facts

Bauxite was first discovered in 1821 by geologist Pierre Berthier near the village of Les Baux in southern France, from which it takes its name.

Field identification & locations

Identify by its distinctive 'pisolitic' texture resembling clusters of small peas or spheres; found commonly in Australia, Guinea, Brazil, and Jamaica. Collectors look for well-defined pisolites and varied coloration.