TiO2 97-98% Specific Gravity 3.8 - 3.9Refractive Index 2.56.5 - 8Mositure 0.4% max.Water Soluble Matter 0.5% max.Titanium dioxide (TiO2) is a white mineral substance that occurs naturally in several kinds of rock and sand. It is chemically inert, thermally stable, non-flammable, non-hazardous, and poorly soluble in water.