El-Gabal el-Ahmar Arabic: الجبل الأحمر is located today within the boundaries of modern-day Cairo, in the area of Nasr City, (30.05 N, 31.3 E) . The name means "The Red Hill". The site was in full production in the times of Akhenaton, Amenhophis III, Tutankhamon and Ramses III. The quarry was directed by Huy also known as "Chief of the King's Works" and also by Hori.
The famous Colossi of Memnon are made from blocks of quartzite sandstone probably quarried at el-Gabal el-Ahmar.
Typical minerals known from this site:
References
El-Gabal el-Ahmar Wikipedia(Text) CC BY-SA