The easy-magnetization axis of mordenite zeolite was determined using commercially available mordenite powder. The well-dispersed suspension of the powder was consolidated by slip casting in a 12-T static magnetic field. The thick bulk deposit was cut into a dice in order to investigate the XRD patterns from the mutually orthogonal surfaces of the consolidated mordenite compacts, the normal lines of which surfaces were parallel and perpendicular to the applied magnetic field. The easy-magnetization axis of mordenite was determined to be the b axis based on the XRD measurements.