Due to a combination of high hardness and toughness, resulting in excellent wear resistance, cemented carbides are commonly used as the rock crushing component in rock drilling. The present paper presents a unique study where the very initial stages of deformation and wear of cemented carbide in sliding contact with rock are followed in small incremental steps. After each step, a pre-determined area within the wear mark is characterized using high resolution SEM and EDS. This facilitates analysis of the gradual deformation, material transfer, degradation and wear. The deterioration mechanisms found in this sliding test are similar to those observed in actual rock drilling. Cemented carbide grades with different microstructures show significant differences, where a higher amount of Co and a larger WC grain size both are associated to more wear.