Over 200 carbonate rock samples were collected from 33 quarries in Ohio. Quarries were studied and described in detail in order to characterize the nature of the quarry operation, the type of stone being produced, variability in carbonate materials, and the ability to produce a lithologically consistent product. The 200 samples were analyzed by petrographic thin section analysis, scanning electron microscopy, neutron activation, cathode luminescence, x-ray diffraction, sulfur reactivity, chemical analysis, porosimetry, and pore casts. Variations in rock were tested to determine which lithologic features affected reactivity. It was determined that crystallinity, crystal size, porosity, and chemical composition are the major controlling factors. The best sorbent will possess euhedral crystals in the 0.05- to 0.2-mm size range, intercrystalline porosity, and a high calcium content. Dolomites, in general, possess the best texture and several units in Ohio are suitable for use as sorbents.