Imperial Egyptian red porphyry - Roman period

Triangular polished piece of Imperial Egyptian red porphyry.
Roman period
47 x 14 x 9 cm

Ancient red porphyry is a magmatic effusive lithotype characterized by a Bordeaux-red color, composed of a cryptocrystalline matrix in which floating phenocrysts of pale pinkish white are oriented, measuring up to 5 millimeters. It originates from Mons Porphyrites and dates back approximately 630 million years, resulting from dacitic-andesitic volcanic activity that led to the formation of extensive layers of effusive material, including tuffs and ignimbrites.
Despite its breathtaking beauty, this material is notoriously difficult to work with due to its hardness. The quarries, located in the stark isolation of the Eastern Egyptian Desert, were situated along caravan routes that connected the commercial hubs of the Nile Valley and Coptos with the ports of Myos Hormos and Berenice, facilitating trade towards India and Arabia.
These quarries were so remote and rugged that they were forgotten for centuries, only to be rediscovered and explored by Burton and Wilkinson between 1882 and 1883. In antiquity, these quarries were of such significance that they were managed directly by the imperial entourage.
There are six known quarries that produce this type of material, all located on the eastern side of the mountain at varying altitudes relative to Wadi Abu Maamel, which intersects the area. The short distances between the quarries ensure a wide variability in appearance and characteristics. For example, the matrix is generally characterized by phenocrysts that range in pinkish hues, but in the quarry northwest of Wadi Abu Maamel, the feldspars appear white. Locally, a brecciated variety is found, while in the northeast, the andesite is black, as it has not undergone the intense alteration typical of ancient red porphyry, lacking the significant amounts of hematite and piemontite responsible for its deep red color.
Among all ancient materials, red porphyry perhaps exudes the most symbolism; it represents a symbolic essence, epitomizing divinity, power, and courage. Its hardness made it challenging to work with—suggesting it was relatively underused during the time of the pharaohs for this very reason—yet it remains the most significant and expensive stone, symbolizing divine power and representing nobility, prestige, and wealth.
During the Roman Empire, demand for red porphyry surged, and the stone was used in grand structures such as the Pantheon and various imperial palaces. Its association with imperial authority was so strong that laws were enacted to restrict its use to the elite. The term "imperial" highlights this exclusivity, reinforcing the stone’s connection to power and prestige.
The routine use of ancient red porphyry was unthinkable, as it symbolized both the imperial house and the gods, later becoming a symbol of Christianity and the martyrdom of Christ. The emperor was crowned on a throne made of ancient red porphyry. The title "porphyrogénn?tos," Latinized as Porphyrogenitus ("born in the purple"), was conferred upon a prince or princess if, and only if—beyond other specific conditions—they were born in the Porphyra, the Purple Chamber of the Great Palace of Constantinople, which overlooked the Sea of Marmara and was entirely adorned with imperial porphyry.