This is an intrusion of peralkaline granite. No other details have been traced. A paper describing a riebeckite granite lying to the south of Abu Durba was only seen after it was too late to incorporate it fully into this book. This is Gabal Musa, which is located in southern Sinai at 28°30 - 28°35’N; 34°05’-34°00’E (El Tokhi, 1998). The complex covers 66 km2 and includes biotite granite, quartz monzonite, quartz diorite and a volcanic sequence, as well as riebeckite granite.