Discovery of a Bronze Age dye workshop reveals secrets of history's most precious pigment

For thousands of years, one color rose above all others — and was worth more than its weight in gold, according to a fourth-century imperial edict.

Tyrian purple was a highly prized pigment developed in the Bronze Age, and it retained its status into the late medieval period. The ancient Greeks and then the Romans revered the royal color, produced from Mediterranean sea snails, for its resistance to fading. But with the eventual fall of the Byzantine Empire, the recipe was lost.

During an excavation of two early Mycenaean buildings discovered on a Greek island, archaeologists unearthed several pottery fragments with residue of 3,600-year-old Tyrian purple dye. The well-preserved pigment could still be used to dye textiles today. The researchers also found crushed mollusk shells and various stone tools believed to be used in the dye-making process.

The pigment, alongside the other remnants of an early functioning purple dye workshop uncovered at the ancient site, has shed some light on the mysteries still surrounding the once highly sought-after color.

The earliest recorded production of Tyrian purple dates back to the Middle Bronze Age. A combination of secrecy around the process and a lack of early archaeological evidence likely led to the recipe being lost. It took hundreds of years of research plus modern experimentation to get close to the presumed procedure.

Creating the historic hue required a large number of sea snails found along the coast of the Mediterranean Sea. Dye artisans commonly sought specific species of snails. Tyrian purple is often described as being a deep reddish purple but the shade could vary depending on the snail used and the amount of heat exposure.

The process of extracting the dye from the snails was laborious and came with a fishy odor. The snails had to be kept alive until the purple dye makers were ready to crush them and extract the mollusk’s mucus glands. The remains of the snails would then be exposed to regulated heat for several days as the color transformed. One estimate said it could take upward of 12,000 snails to get 1 gram of dye, but modern experiments have shown that fewer snails can yield the same amount.

The individuals who wore purple during the Bronze Age remain a mystery, but it is often assumed that the color was only worn by people of prominence due to the dye’s intricate process. In ancient Rome, the color was reserved for the elite and royalty only. The newly discovered workshop appears to be on the smaller side, which could indicate that the dye was used more commonly by those living on the island.

The deep and long-lasting color of Tyrian purple was highly valued in ancient times. The discovery of an ancient purple dye workshop has provided insight into the production process and the significance of the color in ancient societies. The mystery surrounding the individuals who wore purple and the secrets of the dye-making process still remains.