sedimentary
Bauxite
Bauxite (Al2O3·2H2O)
Hardness: 1-3 (Mohs scale), Color: Yellowish-brown, tan, or grey, Luster: Dull/earthy, Structure: Often pisolitic (pea-like) or earthy, Specific Gravity: 2.0-2.5
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Physical properties
Hardness: 1-3 (Mohs scale), Color: Yellowish-brown, tan, or grey, Luster: Dull/earthy, Structure: Often pisolitic (pea-like) or earthy, Specific Gravity: 2.0-2.5
Formation & geological history
Formed as a residual soil in tropical and subtropical regions through the intense chemical weathering of rocks high in aluminum silicates (lateritization).
Uses & applications
Primary ore of aluminum (used for foil, cans, aerospace, and construction). Also used in refractories, abrasives, and chemical industries.
Geological facts
Bauxite is named after the village of Les Baux in southern France, where it was first discovered in 1821 by geologist Pierre Berthier.
Field identification & locations
Identify in the field by its earthy, clay-like appearance, non-crystalline texture, and often its pisolitic (spherical) concretions. Found in regions like Australia, Guinea, and Brazil.
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