Tags: Chemical Substance, Mineral.
Halloysite is a 1:1 aluminosilicate clay mineral with the empirical formula Al2Si2O5(OH)4. Its main constituents are aluminium (20.90%) silicon (21.76%) and hydrogen (1.56%). Halloysite typically forms by hydrothermal alteration of alumino-silicate minerals. It can occur intermixed with dickite kaolinite montmorillonite and other clay minerals. X-ray diffraction studies are required for positive identification.
