Ruflux 61. 200 mesh rutile. 94-96% TiO2. 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 ilmenite, a ferrous titanate, and pure, white titanium dioxide.
For more information on rutile, see the Digitalfire.com Reference Library of ceramic materials.