Gibbsite


Also found in: Dictionary, Thesaurus, Wikipedia.
Related to Gibbsite: goethite, diaspore, boehmite, Brucite

gibbsite

[′gib‚zit]
(mineralogy)
Al(OH)3 A white or tinted mineral, crystallizing in the monoclinic system; a principal constituent of bauxite. Also known as hydrargillite.

Gibbsite

 

(also hydrargillite), a mineral with the chemical composition Al[OH]3. It contains 65.4 percent alumina (A1203); admixtures of Fe3+ and Ga3+ that replace Al3+ in the structure are known. Gibbsite crystallizes in a monoclinic system. Its crystalline structure is of the layer type and consists of bifoliate (OH) packets, in the midst of which Al3+ ions are distributed. Good cleavage occurs along weak interpacket bonds. Gibbsite forms small laminar crystalline particles, usually colorless with a pearly luster, as well as powdery aggregates and incrustations with a radiated or imbricate microstructure. Its hardness on the mineralogical scale is 2.5-3.5; its density is 2,300-2,400 kg/m3. It usually forms upon weathering of alumina-rich rocks. Together with the other hydroxides of aluminum (diaspore and boehmite) and iron, gibbsite is found in bauxite ores. Gibbsite bauxites are among the best aluminum ores.

References in periodicals archive ?
The identified peaks are from the minerals kaolinite (K), gibbsite (G), quartz (Q), and hematite (H).
Equatorial and tropical weathering of recent basalts from Cameroon: allophanes, halloysite, metahalloysite, kaolinite and gibbsite, pp.
Key words: Mineralogical, petrographical, lithofacies, Salt Range, Permian, Cretaceous, kaolinite, goethite, boehmite, gibbsite, dickite, glauconite, chamosite, chlorite, nacrite, micrite, microclasts.
The bauxite zone is characterised by gibbsite and varies from 1m to 8m in thickness.
Gibbsite is present in Oxisols derived from limestone (Ak1) and basalt (Ti1, Ti2, Ti3, Nb1, Nb2) under more humid conditions.
MINERALS Level of abundance JSO-1/JSO-2 JSO-2 * Contamination soils Allophane +++ +++ + Quartz + + - + Plagioclase - + X K-feldspar X - X Augite - + X Gibbsite + - + X Hematite - - X Magnetite - - + 7A halloysite X - X Orthopyroxene X X + - Hydrated halloysite X - X Olivine - - + Glass + - + - +++ abundant; + -: common; +: existent; -: rare, X: not detected * Terashima et al.
In this way the pH dependence of the electrokinetic behaviour of the two layer silicates can be rationalized by comparison with the electrokinetic behaviour of silica and gibbsite or brucite as appropriate.
In the literature, nanoencapsulation of colloidal nanoparticles has included metals (Au, Ag, Fe/Fe2O3), semiconductors (CdS, ZnS, CdSe/ZnSe), polymers (polystyrene, polydimethylsiloxane), and inorganic oxides (boehmite rods, gibbsite platelets).
The various Fe and Al oxide minerals, including hematite, goethite, and gibbsite, are the most common nonsilicate clay colloids found in most soils.
1]) Soil organic matter (humus) 200 (pH dependent) Vermiculite clay 150 Montmorillion ite clay 100 Smectite 100 Allophane 30 Chlorite 30 Illite clay 30 Micas 30 Kaolinite clay 8-10 Gibbsite (Al mineral) 4 Goethite (Fe mineral) 4 TABLE 20-3 Classifications for Salt-Affected Soils Normal Saline Sodic Soils Soils Soils EC < 4dS [m.
The most commonly associated minerals include weloganite, cryolite, strontianite, dawsonite, celestine, elpidite, marcasite, gibbsite, quartz, hematite, goethite, siderite, fluorite, analcime, albite, baddeleyite and calcite.
The ore contains minor amounts of kaolin, talc, gibbsite, manganese (as wad) and chromite.