Boulder of Imperial Porphyry

Egypt

600 Million years old

Reputedly discovered during the reign of Tiberius, this rare stone was quickly prized for its vibrant hues of purple and red, which shimmered and glowed like embers. Most say the name porphyry derives from the Greek word for purple, but others believe it originated from the Sanskrit pur-phu, “red hot embers”.

Pliny marvelled at the fiery luminosity of porphyry, which he described as "the colour of congealed blood, blackish at first glance but gleaming red when held to the light." It was used extensively in Roman art and architecture, and was highly valued throughout the medieval world.

The story of porphyry is not without its mysteries. According to the Byzantine historian Alexander Vasiliev, the site of the quarry where porphyry was mined was lost to history as a direct result of the Council of Chalcedon in 451. It wasn't until Sir John Wilkinson's geological expedition in the early 19th century that the location of the quarry was finally rediscovered.