1.1 ,This test method covers the determination of relative X-ray diffraction intensities of zeolites having the faujasite crystal structure, including synthetic Y and X zeolites, their modifications such as the various cation exchange forms, and the dealuminized, decationated, and ultrastable forms of Y. These zeolites have cubic symmetry with a unit cell parameter usually within the limits of 24.2 and 25.0 Å, (2.42 and 2.50 ,nm).