sedimentary
Bauxite
Al2O3·2H2O (Aluminum Hydroxide)
Hardness: 1-3 Mohs, Color: reddish-brown, grayish, or white, Luster: dull to earthy, Structure: pisolitic (pea-like) or massive, Specific Gravity: 2.0-2.5
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Physical properties
Hardness: 1-3 Mohs, Color: reddish-brown, grayish, or white, Luster: dull to earthy, Structure: pisolitic (pea-like) or massive, Specific Gravity: 2.0-2.5
Formation & geological history
Formed through the intense chemical weathering (lateritization) of aluminum-rich rocks in tropical or subtropical climates. It is typical of the Tertiary and Cretaceous periods.
Uses & applications
The primary ore of aluminum globally. Used in the production of aluminum metal, abrasives, refractories, and chemicals.
Geological facts
Bauxite is not a single mineral but a mixture of hydrous aluminum oxides like gibbsite, boehmite, and diaspore. The location provided (southern Nigeria) is geologically consistent with lateritic deposits where bauxite is found.
Field identification & locations
Identify by its distinctive 'pea-like' (pisolitic) circular structures and earthy texture. Commonly found in tropical rainy zones with good drainage. Collectors look for well-defined pisoliths.
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