sedimentary
Bauxite
Bauxite (mixture of hydrous aluminum oxides: Al(OH)3 & AlO(OH))
Hardness: 1-3 Mohs (soft to the touch), Color: Reddish-brown, yellow, or grey, Luster: Dull to earthy, Structure: Pisolitic (pea-sized round grains) or massive, Specific Gravity: 2.0-2.5
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Physical properties
Hardness: 1-3 Mohs (soft to the touch), Color: Reddish-brown, yellow, or grey, Luster: Dull to earthy, Structure: Pisolitic (pea-sized round grains) or massive, Specific Gravity: 2.0-2.5
Formation & geological history
Formed through the intense chemical weathering of rocks in hot, humid tropical or subtropical climates, which leaches away silica and results in the accumulation of aluminum oxides.
Uses & applications
Primary ore of aluminum; used in the manufacture of aluminum metal, abrasives, refractories, and chemical industries.
Geological facts
Bauxite is not a single mineral but a mixture of mineral species including gibbsite, boehmite, and diaspore. It was first discovered in 1821 by geologist Pierre Berthier near the village of Les Baux in France.
Field identification & locations
Identify by its 'pisolitic' texture, which looks like a mass of small, rounded pebbles or peas cemented together. Often found in tropical regions like Australia, Guinea, and Brazil.
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