"Kaolin" redirects here. For other uses, see Kaolin (disambiguation).
See also: Aluminium silicate
Kaolinite
General
Category
Phyllosilicates Kaolinite-serpentine group
Formula (repeating unit)
Al2Si2O5(OH)4, or in oxide notation: Al2O3·2SiO2·2H2O
IMA symbol
Kln[1]
Strunz classification
9.ED.05
Crystal system
Triclinic
Crystal class
Pedial (1) (same H-M symbol)
Space group
P1
Unit cell
a = 5.13 Å, b = 8.89 Å c = 7.25 Å; α = 90° β = 104.5°, γ = 89.8°; Z = 2
Identification
Color
White to cream, sometimes red, blue or brown tints from impurities and pale-yellow; also often stained various hues, tans and browns being common.
Crystal habit
Rarely as crystals, thin plates or stacked. More commonly as microscopic pseudohexagonal plates and clusters of plates, aggregated into compact, claylike masses.
Kaolinite (/ˈkeɪ.ələˌnaɪt,-lɪ-/KAY-ə-lə-nyte, -lih-; also called kaolin)[5][6][7] is a clay mineral, with the chemical composition Al2Si2O5(OH)4. It is a layered silicate mineral, with one tetrahedral sheet of silica (SiO4) linked through oxygen atoms to one octahedral sheet of alumina (AlO6).[8]
Kaolinite is a soft, earthy, usually white, mineral (dioctahedral phyllosilicate clay), produced by the chemical weathering of aluminium silicate minerals like feldspar. It has a low shrink–swell capacity and a low cation-exchange capacity (1–15 meq/100 g).
Rocks that are rich in kaolinite, and halloysite, are known as kaolin (/ˈkeɪ.əlɪn/) or china clay.[9] In many parts of the world kaolin is colored pink-orange-red by iron oxide, giving it a distinct rust hue. Lower concentrations of iron oxide yield the white, yellow, or light orange colors of kaolin. Alternating lighter and darker layers are sometimes found, as at Providence Canyon State Park in Georgia, United States.
Kaolin is an important raw material in many industries and applications. Commercial grades of kaolin are supplied and transported as powder, lumps, semi-dried noodle or slurry. Global production of kaolin in 2021 was estimated to be 45 million tonnes,[10] with a total market value of $US4.24 billion.[11]
^"kaolinite". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 25 January 2021.
^"kaolinite". The American Heritage Dictionary of the English Language (5th ed.). HarperCollins.
^Deer WA, Howie RA, Zussman J (1992). An Introduction to the Rock-forming Minerals (2nd ed.). Harlow: Longman. ISBN 9780470218099.
^Pohl WL (2011). Economic geology: principles and practice: metals, minerals, coal and hydrocarbons – introduction to formation and sustainable exploitation of mineral deposits. Chichester, West Sussex: Wiley-Blackwell. p. 331. ISBN 9781444336627.
^'U.S. Geological Survey, Mineral Commodity Summaries, January 2022' USGS, 2022.
^'Kaolin Market Size, Share & Trends Analysis Report By Application, By Region And Segment Forecasts, 2022 - 2030. Grand View Research, 2022
Kaolinite (/ˈkeɪ.ələˌnaɪt, -lɪ-/ KAY-ə-lə-nyte, -lih-; also called kaolin) is a clay mineral, with the chemical composition Al2Si2O5(OH)4. It is a layered...
dimension, the Death Busters acquire human host bodies to act through with Kaolinite and Professor Tomoe as acting leaders. Based in Mugen Academy (無限学園, Mugen...
Metakaolin is the anhydrous calcined form of the clay mineral kaolinite. Rocks that are rich in kaolinite are known as china clay or kaolin, traditionally used...
material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, Al2Si2O5(OH)4). Most pure clay minerals are white or light-coloured,...
includes the minerals kaolinite, dickite, halloysite, and nacrite (polymorphs of Al2Si2O5(OH)4). Some sources include the kaolinite-serpentine group due...
shales and other mudrocks. The clay minerals represented are largely kaolinite, montmorillonite and illite. Clay minerals of Late Tertiary mudstones...
between the United States and Canada. The original active ingredients were kaolinite and pectin. In the US, the active ingredient is now bismuth subsalicylate...
Serpentine subgroup (part of the kaolinite-serpentine group in the category of phyllosilicates) are greenish, brownish, or spotted minerals commonly found...
alteration[citation needed] of wall rock which introduces clay minerals including kaolinite, smectite and illite. The process generally occurs at low temperatures...
ternary materials (Si-Al-O). Kaolinite is a quaternary material (Si-Al-O-H). Also called aluminium silicate dihydrate, kaolinite occurs naturally as a mineral...
goethite (FeO(OH)) and haematite (Fe2O3), the aluminium clay mineral kaolinite (Al2Si2O5(OH)4) and small amounts of anatase (TiO2) and ilmenite (FeTiO3...
silicon, 1.56% hydrogen and 55.78% oxygen. It has the same composition as kaolinite, nacrite, and halloysite, but with a different crystal structure (polymorph)...
most common type of mineral in the subgroup. It is also a member of the kaolinite-serpentine group. Lizardite may form a solid-solution series with the...
plutonic igneous rock. When exposed to weathering, it reacts to form kaolinite (Al2Si2O5(OH)4, a sedimentary mineral, and silicic acid): 2 KAlSi3O8 +...
humic acid, peaty soils than the known binding "fixation" that occurs on kaolinite rich clay soils, many marshy areas of Ukraine had the highest soil to...
a ceramic material made by heating raw materials, generally including kaolinite, in a kiln to temperatures between 1,200 and 1,400 °C (2,200 and 2,600 °F)...
laterite. Conversion of kaolinite to bauxite occurs only with intense leaching, as ordinary river water is in equilibrium with kaolinite. Soil formation requires...
non-expansive illite or kaolinite. Too much expansive clay results in uneven drying through the brick, resulting in cracking, while too much kaolinite will make a...
Thomas H. (16 July 2015). "Influence of Nonswelling Clay Minerals (Illite, Kaolinite, and Chlorite) on Nonaqueous Solvent Extraction of Bitumen". Energy &...
Chrysotile General Category Phyllosilicates Kaolinite-serpentine group Formula (repeating unit) Mg3(Si2O5)(OH)4 (ideal) IMA symbol Ctl Strunz classification...
James P. (1980). "pH-independent and pH-dependent surface charges on kaolinite". Clays and Clay Minerals. 28 (6): 412–418. Bibcode:1980CCM....28..412B...
demonstrated in the following reaction, this causes potassium feldspar to form kaolinite, with potassium ions, bicarbonate, and silica in solution as byproducts...
it useful as a binder and as an additive to improve the plasticity of kaolinite clay used for pottery. One of the first findings of bentonite was in the...
(CEC) of illite is smaller than that of smectite but higher than that of kaolinite, typically around 20 – 30 meq/100 g. Illite was first described for occurrences...
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