sedimentary

Bauxite (Aluminum Ore)

Hydrated aluminum oxides, primarily Al(OH)3, AlO(OH)

AI-generated identification · may be incorrect

Hardness: 1–3 Mohs; Color: reddish-brown, white, tan, or yellow; Lustre: dull, earthy; Structure: pisolitic (pea-shaped) or massive; Cleavage: none; Specific Gravity: 2.0–2.5

Hardness: 1–3 Mohs
Color: reddish-brown, white, tan, or yellow

Identified March 22, 2026More sedimentary →

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Physical properties

Hardness: 1–3 Mohs; Color: reddish-brown, white, tan, or yellow; Lustre: dull, earthy; Structure: pisolitic (pea-shaped) or massive; Cleavage: none; Specific Gravity: 2.0–2.5

Formation & geological history

Formed as a residual mineral (laterite) through the chemical weathering of aluminum-rich rocks in tropical or subtropical climates over millions of years.

Uses & applications

Primary source of aluminum for the aerospace, automotive, and construction industries; also used in abrasives, refractories, and chemical processes.

Geological facts

Bauxite is not a single mineral but a mixture of minerals like gibbsite, boehmite, and diaspore. The aluminum manufacturing process (Bayer process) was discovered in 1887.

Field identification & locations

Identify by its 'pea-like' (pisolitic) rounded structures and light weight. Commonly found in tropical regions like Australia, Guinea, and Brazil. Collectors look for unique pisolitic clusters.