New Minerals from the Classic Eifel Region

In the recent four years, the authors have jointly organized and conducted several excursions into the classical volcanic field in the Eifel area, Germany. The original goal was to compare its geochemistry and mineralogy with those of the hyperalkaline intrusions of Khibiny and Lovozero on Kola peninsula, Russia. Since none of us had previous experience with the Eifel area, local amateur mineral collectors were contacted and asked for support. These collectors often have been active in their region for decades and, hence, know the various deposits and minerals by heart. Our request was met with great enthusiasm and invaluable support was given to us not only with respect to the organization of the excursions, but the collectors also shared their experience with getting access to the quarries and often offered samples from their own, very well organized and documented, collections. It soon turned out, that - a bit to our surprise - even in such a classical area as the Eifel with its long tradition of geological and mineralogical research new minerals can be found. As a result, 16 new minerals from the Eifel could be described, accepted by IMA, and the results published. Others are still under study. Some of these minerals were found in the field, others were donated by local mineral collectors. In acknowledgement of their invaluable contribution, several minerals now bear names of those or other local collectors. Several of the new minerals belong to well-known mineral groups, but a few represent quite new structures. For example, in the mineral hielscherite, the pyramidal sulfite anion substitutes for planar carbonate in thaumasite, and günterblassite is the first phyllosilicate with a triple tetrahedral layer, thus indicating somehow a structural transition into a tectosilicate.