Scandium(III) Oxide or scandia is a inorganic compound with formula Sc2O3. The appearance is fine white powder of cubic system. It has different expressions like scandium trioxide, scandium(III) oxide and scandium sesquioxide. Its physico-chemical properties are very close to other rare earth oxides like La2O3, Y2O3 and Lu2O3. It is one of several oxides of rare earth elements with a high melting point. Based on present technology, Sc2O3/TREO could be 99.999% at highest. It is soluble in hot acid, however insoluble in water.