Scandium ammonium sulphate, Sc₂(SO₄)₃.3(NH₄)₂SO₄

Scandium ammonium sulphate, Sc₂(SO₄)₃.3(NH₄)₂SO₄, resembles the potassium salt closely (Meyer and Winter). When its aqueous solution is boiled, the sparingly soluble double salt, Sc₂(SO₄)₃.2(NH₄)₂SO₄, separates out (Meyer and Drapier).