Dickite (Al 2Si 2O 5(OH) 4) is a phyllosilicate named after the metallurgical chemist Allan Brugh Dick, who first described it. It is chemically composed of 20.90% aluminium and 55.78% oxygen. It has the same composition as kaolinite, but with a different crystal structure (polymorph). Dickite sometimes contains impurities such as titanium , iron and potassium
Dickite occurs with other clays and requires x-ray diffraction for its positive identification. Dickite is an important alteration indicator[clarification needed systems as well as occurring in soils and shales.
Dickite's type location is in Pant-y-Gaseg, Wales Dickite appears in locations with similar qualities and is found in China , France, United States and Canada