ingredient information
Kaolin" redirects here. For the Sailor Moon character, see Death Busters#Kaolinite. Kaolinite General Category Silicate mineral Chemical formula Al2Si2O5(OH)4 Crystal symmetry Triclinic pedial H-M symbol: (1) Space group: P1 Unit cell a = 5.13 Å, b = 8.89 Å, c = 7.25 Å; a = 90°, ß = 104.5°, ? = 89.8°; Z = 2 Identification Color White, sometimes red, blue or brown tints from impurities Crystal habit Rarely as crystals, thin platy or stacked, More commonly as microscopic pseudohexagonal plates and clusters of plates, aggregated into compact, claylike masses Crystal system Triclinic Cleavage Perfect on {001} Tenacity Flexible but inelastic Mohs scale hardness 2–2.5 Luster Pearly to dull earthy Streak White Specific gravity 2.16–2.68 Optical properties Biaxial (–) Refractive index na = 1.553–1.565, nß = 1.559–1.569, n? = 1.569–1.570 2V angle Measured: 24° to 50°, Calculated: 44° References [1][2][3] Kaolinite is a clay mineral, part of the group of industrial minerals, with the chemical composition Al2Si2O5(OH)4. It is a layered silicate mineral, with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet of alumina octahedra.[4] Rocks that are rich in kaolinite are known as kaolin or china clay.[5] The name is derived from Kao-ling (Chinese: ??/??; pinyin: Gaoling), a village near Jingdezhen, Jiangxi province, China.[6] The name entered English in 1727 from the French version of the word: "kaolin", following Francois Xavier d'Entrecolles's reports from Jingdezhen.[7]