Durability of armourstone is a very important consideration in breakwater design, as armourstone in breakwaters should be in service for a number of years. Therefore, it is necessary to investigate the long-term performance and quality of the armourstone. Armourstone durability relates to the basic properties of quarry rock together with the environment to which it is exposed. In this study, the properties Of limestones used as armourstone with known durability characteristics in two rubble mound breakwaters near Mersin (Turkey) were investigated and various field and laboratory tests performed. The test results were compared with their site performances in breakwaters. Among the studied stones, two levels of limestone in one quarry displayed very poor performance. The other limestones are found to be good. MgSO4 for Tirtar Middle limestone, point load strength index for Tirtar Upper limestone, wet-dry loss For Degirmencayi, limestone, and Los Angeles abrasion for Tirtar Middle limestone cannot predict the field performance of the armourstone. Therefore, the quality class boundaries of parameters for armourstone should be re-evaluated oil the basis of these test results and field performance.