This standard describes methods for the determination of mineralogical phases typically apparent in nitride and oxy-nitride bonded silicon carbide refractory products using a Bragg-Brentano diffractometer. It includes details of sample preparation and general principles for qualitative and quantitative analysis of mineralogical phase composition. Quantitative determination of -Si3N4, -Si3N4, Si2ON2, AlN, and SiAlON are described.NOTEFor the refinement procedures the total nitrogen content, analysed in accordance with EN 12698-1 is needed.