Basic mechanical properties of single crystal gallium nitride are measured. A Vickers (diamond) indentation method was used to determine the hardness and fracture toughness under an applied load of 2N. The average hardness was measured as 12±2 GPa and the average fracture toughness was measured as 0.79±0.10 MPa√m. These values are consistent with the properties of brittle ceramic materials and about twice the values for GaAs. A methodology for examining fracture problems in GaN is discussed.