Archeologists Find a Lost Ancient Pigment That Was More Valuable Than Gold

In 2023, archaeologists and volunteers discovered a lump of soft, purple substance at a Roman bathhouse site in Carlisle, northern England. Tests had shown that the substance contained beeswax and bromine. According to the release, the pigment had been made by crushing thousands of seashells from the Mediterranean, North Africa, and Morocco. It had been difficult to produce and very expensive, which had made it more valuable than gold at the time.

Researchers believed the pigment had been made from the secretions of three types of sea snails, each producing a different color: Hexaplex trunculus (bluish purple), Bolinus brandaris (reddish purple), and Stramonita haemastoma (red). According to the University of Chicago Library , "It had been a complex process that had involved extracting the liquid while the mollusk was still alive and exposing it to sunlight for a specified period, during which the dye had changed color. It had taken up to 12,000 mollusks to produce 1 gram of dye."

Knewz.com noted that the purple sample had been used for painting frescoes or dyeing clothes. Ancient writers had been very specific about the color—a deep reddish-purple, similar to darkened blood, with a hint of black. According to the BBC , Pliny the Elder had described it as having a "shining appearance when held up to the light." During that period, Tyrian purple had been worn by the most privileged people as a symbol of power, authority, and wealth. The excavation site also revealed over 2,800 significant finds, including coins, gemstones, and two large stone heads.

Frank Giecco, the technical director of the organization leading the excavation project, had said, "It had been an incredibly rare find, especially in Europe. It's the only example we know of in Northern Europe—possibly the only example of a solid sample of the pigment in the form of unused paint pigment anywhere in the Roman Empire." Giecco also noted that examples had been found in wall paintings (like in Pompeii) and some high-status painted coffins from the Roman province of Egypt.

The purple pigment was believed to have first been made in the 2nd millennium B.C. by the Phoenicians, an ancient people from the Mediterranean region now recognized as Lebanon. The pigment had been produced in Tyre, one of the oldest cities in Lebanon, as well as in other Mediterranean areas like North Africa.

Giecco had explained to IFL Science , "For millennia, Tyrian Purple was the world’s most expensive and sought-after color. Its presence in Carlisle combined with other evidence from the excavation strengthens the hypothesis that the building was in some way associated with the Imperial Court of the Emperor Septimius Severus which was located in York and possibly relates to an Imperial visit to Carlisle."

After the Romans had invaded Britain from A.D. 43 to A.D. 410, Carlisle, located near Hadrian's Wall, marked the edge of the Roman Empire and the unexplored lands to the north. Cumberland Council councilor Anne Quilter said in the press release per Newsweek , "Following the discovery of the two Roman monumental heads and the other precious items, the project had unearthed some fascinating and globally significant finds. More digs had been planned, as well as the opportunity to visit the site and see the groundbreaking work underway."