Mineral Deposits are enriched 10 to 10000 times the geochemical abundance. These resources have a limit; some authors have defined the depletion of some ore deposits for the beginning of century 21 as germanium, tin, mercury, bismuth, cadmium, nickel and tungsten. A forecasting for copper price should reach 3.9 US$/lb in 2010.An analysis of active, inactive and future mines data base, using mathematical models of grade-tonnage diagrams, give the possibility to redefine the critical grade and its estimation, and also to calculate the total tonnage on the earth crust. Therefore, resources could be classified as optimistic or pessimistic availability.Based on grade-tonnage diagrams , the relation of oxide type nickel deposits indicated that all mines have ore grade higher than critical grade, then the resources are categorized as optimistic. On the other hand, in the case of porphyry type cupper deposits suggested belong to the pessimistic group. Other minerals as lead, zinc, molybdenum, tungsten, uranium, gold, and silver were also studied. This method, where critical grade and total mineral resources are estimated, let have an approximation to forecasting to the prices trend and a global bases for the exploration and mining business.