Many powdered materials tend to become oriented when mounting them in the various x-ray sample holders. Among the more easily oriented materials are the clay minerals. It has been found necessary therefore to be extremely careful in the preparation of the powdered clay sample for x-ray diffraction examination. To minimize orientation, the sample must not be pressed into the specimen holder from the side that will be exposed to the x-ray beam. In order to obtain satisfactory conditions for clay samples with the Norelco low angle rotation specimen holder it was necessary to modify the holder so that orientation effects were minimized.