Oman Oman Limestone Mining Mining Plant MC World. limestone mining in oman. OMAN271 . By the end of 2009, about 500 active industrial minerals mining operations were active in Oman, including 150 for landfill material, 183 for crushed stone, 71 for chromium, 57 for marble, 4 each for clay, gypsum, and laterite, 3 for sandstone, 2 for limestone, and 1 for salt ODriscoll, 2010.