Emerald mines (incl. Gebel Zabara; Wadi Abu Rusheid; Wadi Gimal; Wadi Sikait; Wadi Umm Debaa; Wadi Umm Kabu), Sikait-Zabara region, Eastern Desert, Red Sea, Egypt
Ancient emerald mines (2000 B.C. - 1200 A.D.). Rediscovered 1818. Egypt was the source of almost all emerald in ancient times.
The area is underlain by quartz-micaceous, hornblende, biotite, and talc schists, crumpled into complex folds and squeezed between a massif of the late Gattar gneissic granites and serpentinites. Emerald
-bearing biotite and biotite-amphibole-talc schist horizons are up to 10 m thick.
crystals are generally small, and most contain fissures and numerous inclusions. Their colour is light green, occasionally bluish green. Associated minerals including those that form inclusions in the emerald
, are biotite, quartz, hornblende, less abundant plagioclase, tourmaline (schorl), garnet, magnetite, and calcite. Gas-liquid inclusions often contain carbon dioxide.
Ref: E.Ya.Kievlenko, Geology of gems, 2003, p. 86