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Bauxite
Bauxite - Mineral Properties and Uses |
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What is Bauxite? |
Bauxite is a rock composed mainly of aluminum oxide and aluminum hydroxide minerals. These might include: gibbsite, boehmite and diaspore. The rock usually includes other materials such as iron hydroxides, clay, silt and free silica. It most often occurs as a residual soil material in tropical and subtropical areas. It is the primary source of aluminum. |
Uses |
Bauxite is the most common ore of aluminum. It is also used as an abrasive, however, this use is now being replaced by synthetic materials. |
Color |
white, gray, yellow, red |
Streak |
normally white but may streak other colors if the specimen is stained |
Luster |
dull to earthy |
Diaphaneity |
translucent |
Cleavage |
because bauxite is a mixture of gibbsite, boehmite and diaspore, it has no cleavage properties of its own |
Hardness |
1 to 3 |
Specific Gravity |
2 - 2.5 |
Distinguishing Characteristics |
pisolitic structure, color |
Crystal System |
Bauxite is a mixture of Diaspore (orthorhomic), Gibbsite (monoclinic), and Boehmite (orthorhombic) |
Chemical Classification |
oxide / hydroxide |
Chemical Composition |
gibbsite, Al(OH)3
boehmite, AlO(OH)
diaspore, AlO(OH) |
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Bauxite from Little Rock, Arkansas.
Specimen is approximately 4 inches (10 centimeters) across.
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Pisolitic structure of bauxite mineral from Little Rock, Arkansas.
A detailed view of the specimen shown above..
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Bauxite from Demerara, Guyana.
Specimen is approximately 4 inches (10 centimeters) across.
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Bauxite from Little Rock, Arkansas.
Specimen is approximately 4 inches (10 centimeters) across.
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Mineral photographs that appear on this page with a Geology.com copyright mark are property of Geology.com and may not be used beyond our website. If you like these photos and would like to share them with others please link to this page or email its URL. The photos were taken and composed by Ann Bryant.
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