Resumen de Génesis y medio de formación del yacimiento de minerales de berilio asociados a la pegmatita de Franqueira, Pontevedra (Galicia)

Dámaso B. Moreiras Blanco, Agustín Martín Izard, Rogelio Daniel Acevedo, A. Paniagua Condado, Celia Marcos Pascual

• The aim of this paper is to describe the geological, mineralogical and geochemical remarks of the Franqueira pegmatitic mineralizations giving raise to a genetic descriptive model. Exometasomatic interaction of Be-rich pegmatitic bodies with dunitic wall-rocks leads to the development of gemstone deposit, several meters thick, formed essentilly of emerald, phenakite and chrysoberyl (alexandrite) in phlogopite gange. Endometasomatic hornblende-pyroxene-garnet facies is also locally developed. The mineralization resambles strongly the emerald-alexandrite type locality from Tokowaja (Oural) although the original dunitic body was this former occurrence not observed.