Kaolinite - Wikipedia. Kaolinite (/ ˈ k eɪ ə l ɪ n aɪ t /) is a clay mineral, part of the group of industrial minerals with the chemical composition Al 2 Si 2 O 5 4.It is a layered silicate mineral, with one tetrahedral sheet of silica (SiO 4) linked through oxygen atoms to one octahedral sheet of alumina (AlO 6) octahedra.
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