Premium calcined airfloated rutile. 95.8% Titanium dioxide; 0.4% iron oxide. 100% < 200 mesh; 96.6% < 325 mesh. Rutile is a natural source of titanium dioxide used in glazes. Increasing amounts cause glaze opacity and, eventually, matte surfaces. Titanate crystallization on cooling can lead to interesting, variegated surfaces. The small % of iron in rutile tends to promote yellowish colours. Other sources of TiO2 for glazes include pure white titanium dioxide and ilmenite, a ferrous titanate.