Born during the XVIIIth century as a science, mineralogy still remains a very "up-to-date" science and, with the rise of modern analysis techniques, its field of application became widely extended. Undoubtedly, most of the important mineralogical species are now discovered. Every year, about one hundred new names are submitted to the commissions of nomenclature which, under the control of the International Mineralogy Association (IMA), authorise new species and discredit insufficiently characterised old minerals. As the result of that severe control, only few tens of new species per annum, generally of very small size, are accepted. But, if it still remains the secret hope of many mineralogists to discover new species, this aspect constitutes only one particular and finally very limited finally feature of the actual mineralogical research activities. Today, mineralogy plays a major role in all domains of Earth Sciences: in Petrography, igneous, metamorphic or sedimentary, every time the petrologist must initially give some interest to minerals constituting the various rocks. Same thing can be said about Structural Geology, Metallogeny or even Geophysics, as it plays with parameters generally interpreted by reference to mineral phases (" olivine " with structure of perovskite, hypothetical phases of the deep mantle or of the Earth's core, etc). Crystallography, which, under its most obvious aspect, geometrical crystallography, was at the origin of the birth of mineralogy, reached recently new domains. It became a very important tool in chemistry (mineral and organic, for the study of the artificial compounds...), in physics (especially solid state physics) or in biology (e.g. structure of proteins). From this evolution, it results in University, a considerable risk, which one can measure by the disappearance rate of the chairs of mineralogy in most of the universities, in the whole world. Being diluted in other disciplines, mineralogy tends to lose its identity, becoming a tool within the hands of other specialists who do not always handle most of the subtleties inherent to that science. It seems important to have in mind the main steps of it's historical development, in order to emphasise all the importance which it keeps within the Earth Sciences: : " the more one knows about minerals, the better Earth Scientists one will be, no matter what one's individual specialisation" (F.C. Hawthorne, Presidential address, Mineralogical Association of Canada, 1992).