Titanium dioxide exists in three modifications with different crystal lattice structures and therefore altering physical properties. These are rutile, anatase and brookite.

Rutile is the modynamically the most stabile form. For that reason, anatase and brookite rearrange at elevated temperatures of 750℃ (brookite) or 915℃ (anatase), respectively,monotropically to rutile, the melting point is from 1830℃ to 1850℃.

It is stable in chemical properties and performance, insoluble in water, organic acid and weak inorganic acid, and soluble in concentrated sulfuric acid, alkali and hydrofluoric acid. It is with excellent pigment performance like strong reducing power and hiding power. Refractive index for rutile is 2.70, and 2.55 for anatase. It is nontoxic