sedimentary

Bauxite

Bauxite (Al(OH)3, γ-AlO(OH), and α-AlO(OH))

AI-generated identification · may be incorrect

Hardness: 1-3 Mohs; Color: reddish-brown, pink, yellow, or grey; Luster: dull to earthy; Structure: Pisolitic (pea-like) or massive; Specific Gravity: 2.0-2.5

Hardness: 1-3 Mohs
Color: reddish-brown, pink, yellow, or grey
Luster: dull to earthy

Identified June 29, 2026More sedimentary →

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Physical properties

Hardness: 1-3 Mohs; Color: reddish-brown, pink, yellow, or grey; Luster: dull to earthy; Structure: Pisolitic (pea-like) or massive; Specific Gravity: 2.0-2.5

Formation & geological history

Formed as a residual soil in tropical and subtropical regions through the intense chemical weathering (laterization) of aluminum-rich rocks like granite or basalt.

Uses & applications

Primary ore of aluminum; used in the production of alumina for smelting, abrasives, refractories, and chemical industries.

Geological facts

Bauxite is named after the village of Les Baux in southern France where it was first discovered in 1821. It is not actually a single mineral, but a mixture of hydrous aluminum oxides.

Field identification & locations

Identify by its distinctive 'pisolitic' texture, where circular or oval nodules (pisolites) are visible in a finer-grained matrix. Found commonly in Guinea, Australia, Brazil, and Jamaica.