Synthetic Rutile: artificial material produced by the “Flame Fusion Method,” chemically a Titanium oxide with the formula TiO2. It has low transparency and is not colorless but generally slightly yellowish. During the 1950s, it was used in jewelry as a Diamond simulant but was gradually replaced by other simulants considered more attractive, such as Fabulite, YAG, GGG, Cubic Zirconia, and Synthetic Moissanite. It crystallizes in the Tetragonal System and is strongly birefringent. It differs from Diamond by its pronounced birefringence (causing doubling of facet edges) and its distinct strong dispersion (0.330), giving it a yellowish appearance visible to the naked eye.
