Thulium Oxide, also called Thulia, is the important dopant for silica-based fibre amplifiers, and also have specialized uses in ceramics, glass, phosphors, lasers. Formula: Tm2O3 CAS No.: 12036-44-1 Molecular Weight: 385.88 Appearance: White Solubility: Insoluble in water, moderately soluble in strong mineral acids Stability: Slightly hygroscopic Purity: Tm2O3/TREO≥ 99.0%