Marble analysis, 50.1322
Gypsum origin: Egypt
Gypsum has been used in Egypt for thousands of years. Deposits are known near Alexandria and Port Saïd, along the Suez Gulf coast, in the Fayoum area, at Qoseir and north of Ourghada on the Red Sea. Thus, a local source close by its discovery site is most probable.
D. Decrouez & K. Ramseyer (1998)