sedimentary

Bauxite

Bauxite (Mixture of Al(OH)3, AlO(OH), and Fe2O3)

AI-generated identification · may be incorrect

Hardness: 1-3 Mohs; Color: reddish-brown, white, tan; Luster: earthy/dull; Structure: Pisolitic (pea-sized round grains) or massive; Specific Gravity: 2.0-2.5.

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

Identified April 13, 2026More sedimentary →

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Physical properties

Hardness: 1-3 Mohs; Color: reddish-brown, white, tan; Luster: earthy/dull; Structure: Pisolitic (pea-sized round grains) or massive; Specific Gravity: 2.0-2.5.

Formation & geological history

Formed through the chemical weathering (laterization) of aluminum-rich rocks in tropical or subtropical climates. It is the primary ore for aluminum and often dates from the Mesozoic to Cenozoic eras.

Uses & applications

Primary source of aluminum; used in metallurgy, chemicals, abrasives, and refractory materials.

Geological facts

Bauxite is not a single mineral but a rock composed mainly of aluminum oxide minerals like gibbsite, boehmite, and diaspore. The red color is usually due to iron oxide impurities.

Field identification & locations

Identify by its distinctive 'pisolitic' circular grain pattern and earthy texture. It is lighter than it looks and lacks a crystalline sparkle. Commonly found in Guinea, Australia, Brazil, and Jamaica.