Coal was the rock that was easy to be burnt that more than 50% -70%heavy his volume was the organic matter that was material karbonanincluding inherent moisture.The organic matter especially that is plants that could take the formof the tracks of tree skin, the leaves, the root, the structure ofwood, spores, polen, resin, et cetera. Calori 6.3 - 6.1 : USD 71/MT. 5.8-5.6