Archaeologists and volunteers stumbled upon an extremely rare object during an excavation of a Roman bath in Carlisle, northern England. The object was a solid sample of Tyrian purple dye, which was highly valued in ancient times for its use as an artificial pigment. The substance is believed to have been produced from large quantities of sea snails, which may have been used for frescoes.
Tyrian purple was first produced by the Phoenicians in the 2nd millennium BC in Tire, a city in Lebanon and one of the world’s oldest continuously inhabited settlements. This pigment is also produced in some other areas of the Mediterranean region, such as North Africa. It is known for its bright purple color and high value, making it reserved for use by the upper class.
The process of producing Tyrian purple is complex and requires collecting thousands of sea snails. Experts estimate that up to 12,000 snails are needed to create just 1 gram of dye. This makes the substance extremely expensive, even more valuable than gold at the time.
Frank Giecco, an archaeologist with mining consultancy Wardell Armstrong who participated in the excavation at Carlisle, said that finding a solid specimen like this one is particularly unusual. “This is the only example we know of from Northern Europe,” he said, “and possibly even the only example anywhere in the Roman empire.”
The Tyrian purple dye sample at Carlisle was likely used to paint frescoes or decorate large public buildings and real estate owned by the upper class. According to Sarah Irving, a spokeswoman for Cumberland Council who collaborated with Wardell Armstrong on the project, this pigment can also be used to dye clothes and paint walls in homes. The discovery has sparked excitement among historians and art enthusiasts alike as it provides insight into how ancient people created their vibrant artwork using natural resources like sea snails and beeswax.