Mons Porphyrites — Wikipedia

Mons Porphyrites (today Gebel Dokhan) is the mountainous site of a group of ancient quarries in the Red Sea Hills of the Eastern Desert in Egypt. Under the Roman Empire, they were the only known source of the purple "imperial" variety of porphyry. They were exploited between the 1st and 5th centuries AD. The other imperial quarries in the Eastern Desert were Mons Claudianus, Mons Ophiates and Tiberiane. These four quarries were probably under a unified administration, since the same procurator metallorum is found in more than one. The quarries were discovered by Caius Cominus Leugas in AD...