Zeolites are often used under mechanical stress, and it is therefore useful to study their mechanical properties for strength design in a wide range of applications. We characterized zeolite A by combining high-energy X-ray diffraction and high-resolution transmission electron microscopy techniques to investigate changes in its atomic arrangement during mechanical amorphization. A decrease in the T鈥揙鈥揟 angle and distortion of the zeolite A lattice framework by compressive stress were confirmed using these techniques. We showed for the first time that at least one of the zeolite amorphization processes is caused by distortion of the framework structure by a compressive stress to form a higher density noncrystalline material.