Yttrium sulphide, Y₂S₃

Yttrium sulphide, Y₂S₃, is a yellow solid which resembles the other rare earth sulphides. A green, crystalline, insoluble double sulphide, Y₂S₃.Na₂S, is obtained by heating a mixture of yttria and sodium chloride to 1000° in a stream of hydrogen sulphide, and washing the product with cold water.