A method of manufacturing such a cerium

PROBLEM TO BE SOLVED : To produce the subject simple and readily handleable abrasive without using an oxidizing agent or a reducing agent and without requiring complicated operations such as pH regulation by using a specific rare earth carbonate and an oxidized derivative of silicon. SOLUTION : (A) A rare earth carbonate containing (i) cerium carbonate and (ii) lanthanum carbonate is dry mixed or wet mixed with (B) an oxidized derivative of silicon and the resultant mixture is then baked. The content of the components (i) and (ii) in the component A is 30-60% expressed in terms of oxides and the weight ratio of the carbonate of the component (i) to the carbonate of the component (ii) is preferably (1 : 1) to (2 : 1) and the mixing weight ratio of the components A to B is preferably (100 : 5) to (100 : 30). The average grain diameter of the mixture is preferably <=10μm and the baking temperature is preferably 800-1, 100 deg.C.