Trace Element Geochemistry and Genesis of Beryl from Wadi Nugrus, South Eastern Desert, Egypt

Abstract

Beryl occurs in the ancient Roman mines at Wadi Nugrus, South Eastern Desert of Egypt. It ranges from small crystals to 10 mm in size, and it varies in color, appearing as bright green, pale green, dark green and brown-green with biotite inclusions. The trace and minor elements were analyzed by the SIMS method. The two rims are richer in Cs, Na, Mg, Fe, Sc, V, Rb and H2O than cores but are poor in Mn, Ca, Co, Sr and Li. The bright-green rim is richer than the pale-green one in Na, P, K, Ca, Fe, Rb, Cs and F, but poorer in Mg and Li. The alkaline elements (Cs, Na, Rb) and Fe correlate with the color zoning, and where beryl crystals have a maximum of these elements, the green color is strong and bright. The emerald of Wadi Nugrus has similarities with the geological setting of the Canadian emeralds. Emeralds occur along the contact zone between biotite schists, pegmatites and quartz veins. A large-scale interaction between Be-bearing magmatic fluids from granites and related pegmatites took place with hydrothermal fluids enriched in Cr, V, Sc, Mg and Ca after percolation through pre-existing serpentinite and talc carbonates, metagabbros and biotite schists and additional fluids bearing H2O, NaCl and CO2.

Assessing environmental and radiological impacts and lithological mapping of beryl-bearing rocks in Egypt using high-resolution sentinel-2 remote sensing images

“…The mean estimated outdoor annual effective dose (AED out ) values are 0.07 mSv y −1 for W. Ghazala, 0.06 mSv y −1 for W. Sedri, 0.16 mSv y −1 for Homret Mukpid, 0.05 mSv y −1 for Igla, 0.11 mSv y −1 for Zabara-Um Addebaa belt and 0.15 mSv y −1 for Homret Akarem, which are comparable with the recommended level of 45 (0.07 mSv y −1 ).…”

“…Abdalla 44 reported Be concentrations with a range of 0.001–0.007% in beryl-bearing granitoids (Homret Akarem, Homret Mukpid, and Qash Amir) in the Eastern Desert of Egypt. Abdel Gawad et al 45 investigated the geochemistry and genesis of beryl crystals (up to 10 mm in size) from the ancient Roman mines at Wadi Nugrus, SED, Egypt. They reported that the emerald of Wadi Nugrus occurs along the contact zone between biotite schists, pegmatites, and quartz veins, and has similarities with the geological setting of the Canadian emeralds 45 .…”

“…Abdel Gawad et al 45 investigated the geochemistry and genesis of beryl crystals (up to 10 mm in size) from the ancient Roman mines at Wadi Nugrus, SED, Egypt. They reported that the emerald of Wadi Nugrus occurs along the contact zone between biotite schists, pegmatites, and quartz veins, and has similarities with the geological setting of the Canadian emeralds 45 . Additionally, Be reached up to 604–1700 ppm in granitic pegmatites (albite or sodic aplite dike) in W. Sikait and Wadi Nugrus areas 50 .…”

“…This index is used to evaluate the released gamma rays more than one meter from the Earth’s surface 40 , 42 – 45 . 226 Ra, 232 Th, and 40 K activity concentrations are used to estimate the D air as follows: where Ra, Th and K are 226 Ra, 232 Th, and 40 K activity concentrations, respectively.…”

“…H in & H ex can be measured to infer the radiation effect on human organs. They can be estimated using the following equations 45 , 46 : …”