The Tribology of crystalline semiconductors and ceramics is critical to the utilization of these materials in high technology applications. For example, semiconductors used for large-scale integrated circuits are cut by diamond impregnated wheels and, lapped and polished in fluids that contain abrasive particles. Ceramics are being used as abrasion resistant coatings in reciprocating engines and other machines where surfaces are moving at a relative velocity so that the ceramic coating is abraded due to inadvertent contact of these surfaces. The contact of an abrasive particle with a crystalline semiconductor or ceramic damages the surfaces of these materials. This damage is detrimental because it creates cracks which can lead to catastrophic brittle failure. There is currently no quantitative model which can predict the mode or extent of this damage. This project develops a unique model and, simple and straightforward tribological experiments that can be used to determine and eventually predict the deformation mechanisms of crystalline semiconductors and ceramics. The results of this research will be valuable to industry and may be utilized to optimize cutting, lapping and polishing crystalline semiconductors and minimize the abrasive wear of ceramic coatings.