The mineral resources industry is the backbone of our economic system, providing essential materials to maintain and improve our standard of living (G. Beaudouin, 2009). Whether we like it or not, we are all called upon to play a vital role in a mining enterprise. The aim of Geological Control of Mining, Volume I, is to describe, explain, interpret and, if possible, predict the steps and methods to be followed, starting with geological investigation, geometrization of deposits, mining geology, categorization of ores and the role of the geologist during mining. The geologist's role is not to discover new ores.