Dysprosium(III) oxide
Dysprosium oxide is a sesquioxide compound of the rare earth metal dysprosium. It is a pastel yellowish-greenish, slightly hygroscopic powder having specialized uses in ceramics, glass, phosphors, lasers, dysprosium metal [halide lamp]s, and as a Faraday rotator.
It can react with acids to produce the corresponding dysprosium salts: