Performance measurements of large-diameter circular diamond saws were conducted on eight different carbonate rocks in marble factories located in some areas of Turkey and hourly slab productions were calculated. Rock samples were collected from these factories for laboratory tests. Triaxial compressive strength test were carried out on each rock type and a brittleness index determined from Mohr's envelope. Slab productions of circular diamond saws and the brittleness index evaluated using both linear and exponential regression analysis. The both regression analysis produced strong correlations between the slab production and the brittleness index. Concluding remark is that the sawability of carbonate rocks can be predicted from the brittleness index determined from Mohr's envelope. However, the validity of the derived equations must be checked for the other rock types.