The preparation of thin sections of rocks and minerals for petrographic examination was ably presented in 1953 by Read and Mergner (1) who summarized the development of thin-sectioning techniques together with a detailed description of the established practice of the U. S. Geological Survey. In recent years, the methods of petrography have become increasingly useful in ceramics and other non-metallic and refractory technology. Recently Insley and Frechette (2) have published a comprehensive work in this field of industrial petrography. In many instances standard methods for preparing thin sections may be applied to ceramic microscopy, but there is an increasing number of articles or materials to which they can be applied with only partial effectiveness or not at all. Included among these are grinding wheels, other abrasive articles, super refractories of silicon carbide and other compounds, and ceramic articles such as sintered alumina products.