A Mineralogia e alguns de seus minerais raros ou de gênese exótica

Abstract

Mineralogy, rare minerals, and species of exotic genesis. The knowledge of the mineral genesis includes a large list with over than 4.000 valid species, can present some special aspects which made those processes different of the normal ones. There are, for instance, seasonal mineral species, which appear in dry seasons and are destructed in wet epochs; or minerals formed by oxidation of carbonatic material samples, only when stored within wooden cases; or a species that is formed by reaction between serpentinite and a licken developed on its surface; or other, whose formation begun since a centennial ship sunk in a river, by water action on tin tools. Such examples, related with others in this paper, show mineral genesis in which time and environmental conditions are quite different of those usually found.