sedimentary

Bauxite

Hydrated aluminium oxides mixture (primarily gibbsite, boehmite, and diaspore)

AI-generated identification · may be incorrect

Hardness varies from 1 to 3 on the Mohs scale depending on composition; color ranges from reddish-brown, pink, white, to yellowish-brown; luster is dull, earthy; lacks distinct crystal structure as it is typically amorphous or pisolitic (composed of rounded bean-like grains); specific gravity is 2.0 to 2.5.

Identified August 1, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the weathering of various aluminous rocks in tropical and subtropical climates, where intense leaching of silica and other soluble materials leaves behind a concentrated residue of aluminum oxides. Age varies widely depending on the deposit.

Uses & applications

The primary ore of aluminum used in metallurgy; also used in abrasives, refractories, and chemicals.

Geological facts

Bauxite was named after the village of Les Baux-de-Provence in southern France, where it was first discovered in 1821 by geologist Pierre Berthier.

Field identification & locations

Identified by its characteristic pisolitic (pebble-like) texture, reddish-brown color, earthy smell when moistened, and softness. Found extensively in Australia, Guinea, Brazil, Jamaica, and China.