gems, beryl, emerald, Egypt, Cleopatra, emerald geology

Geochemical rock sampling and panning of Alluvium suggest the occurrence of a geochemical province of beryllium, in which beryl is the main beryllium mineral, in the Nugrus-Zabara area. The province lies in a NW-SE belt parallel to a deep-seated tectonic zone of the Red Sea trend and extends for about 40 km from Um Kabu in the SE to Zabara in the NW. The province is restricted to certain horizons of mica schists and quartz veins in contact with greisenized and albitized stanniferous granites and is probably developed by pneumatolytic and hydrothermal fluids (developed during the evolution of stanniferous granite magma) which moved along deep-seated tectonic zones. The province is characterized by biotitization, tourmalinization and silicification of the schists and increased concentrations of Be, Sn, Nb, Pb, Y and Cu in the granites, schists, quartz veins and pegmatite dykes. The ancient emerald mines are located within the boundaries of this province.