Titanium Dioxide

Titanium dioxide, also known as titanium(IV) oxide or titania, is the naturally occurring oxide of titanium, chemical formula TiO2. When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. It has a wide range of applications, from paint to sunscreen to food colouring. When used as a food colouring, it has E number E171. Titanium dioxide occurs in nature as well-known minerals rutile, anatase and brookite, and additionally as two high pressure forms, a monoclinic baddeleyite-like form and an orthorhombic I -PbO2-like form, both found recently at the Ries crater in Bavaria.[1][2] The most common form is rutile,[3] which is also the most stable form. Anatase and brookite both convert to rutile upon heating.[3] Rutile, anatase and brookite all contain six coordinated titanium. Titanium dioxide has eight modifications - in addition to rutile, anatase and brookite there are three metastable forms produced synthetically (monoclinic, tetragonal and orthorombic), and five high pressure forms (I -PbO2-like, baddeleyite-like and cotunnite-like):