Since the end of the 18th century, with the systematization of mineralogy as a science, europeans naturalists, noblemen and governors have demonstrated great interest for collections and heaps of rare minerals. Brazil has an incredible variety of rarities and crystals which puts it among the main provinces of the world. A particular case of these minerals are the gem-minerals, whose existence in our territory has influenced the imaginary of portuguese people and "bandeirantes" (members of early brazilian expeditions) in the beginning of the colonization. Many mineral and gem fairs states, which attract a great number of tourists, specially the foreigners.