The art of creating purple dye

Purple dye made from the tiny murex shell pops up on a regular base throughout antiquity. It was an expensive coloring material reserved for royalty and other people of high rank who could afford it. With it, came the symbol of power and prestige which was particularly exploited by the Roman emperors and their ladies parading with their flashy robes.

The fashion seems to have started in ancient Phoenicia, where the shells were widely harvested. As these seafarers settled in new colonies around the Mediterranean, their craft and knowledge soon spread with Carthage at its center. The Romans eyed the wealth and prosperity of Carthage, and that included this much-coveted purple dye. It is not surprising that the emperors took control of this industry since the business was very lucrative. Petra was such a hub where purple cloth and other precious goods transited on their way between Arabia Felix (modern Yemen) and the Mediterranean. The Romans eventually took control of that trade route.

However, purple spread over the ancient world much earlier. The Macedonians, for instance, used purple fabric to wrap the cremated bones of their kings before placing them inside a precious larnax (see: The Tomb of King Philip II of Macedonia). It has been reported that Alexander himself wore purple for everyday use. If we look closely at the mosaic retrieved from the House of the Faun in Pompeii, we recognize the now faded purple-grey of his tunic that originally was deep purple (see: Alexander’s battle outfit).

On several occasions during his campaign in Persia, Alexander’s booty included purple cloth. In Susa alone, he collected more than 100 tons of the precious cloth (see: Alexander’s treasure at Kyinda). This is irrefutable proof that this expensive product was widely available among those who could afford it. In any case, there still was enough material available at the time Alexander organized the Grand Susa Wedding in 324 BC. It has been documented that the floor of his vast ceremonial tent was covered with purple carpets embroidered with gold.

The Persian Empire had amassed an unbelievable amount of wealth since the days of Cyrus the Great. This ruler’s tomb in Pasargadae, for instance, was carpeted with purple rugs. Also the mattress, on which Cyrus’ remains were resting, was colored purple. Median trousers and robes were dyed in a wide range of colors, the most prominent ones being hyacinth and purple.

Persepolis was another place rich with purple draperies and carpets. Diodorus states that the Persian wealth had even rubbed off onto the ordinary people who possessed “garments tainted with sea purple and embroidered with gold.”

The custom of wearing purple was perpetrated down to Seleucos I Nicator as seen on the rare mosaic from Apamea (see: The unique mosaic from Apamea), and to the Indian King Sopeithes, who ruled over a city on the Hydaspes River, tentatively identified as Bhera (see: The realm of King Sopeithes included modern Bhera?)  

This popularity of purple brings me to the next question: How exactly was this Tyrian or Phoenician dye made? The recipe has remained mostly secret until today as only a handful of people around the world knew the techniques involved.

The Archaeology News Network recently published a very revealing article about a man from Tunisia (to which Carthage belonged in antiquity) who started the long quest in search of the tricks of the trade. It is quite amazing to hear that neither archaeologists nor historians or experts in chemistry and dying technique know how to find and recuperate the dye from the murex shell. No historical document apparently provides any detailed information about the production method involved.

[Picture from Archaeology News Network (Credit: Fetih Belaid/AFP)]

Mohamed Ghassen Nouira, who runs a consulting company, had to start his investigation from scratch. Initially, he thought it would be enough to crush the whole shell in the hope of seeing how the concealed sea snail would release its fascinating color. He spent years on the project, confessing that he had to get used to the foul stench first. Who would have thought of that? In the end, he discovered that the dye is contained in the guts of the sea snail. The exact procedure is now a secret this Tunisian is carefully keeping to himself.

Artists, as well as researchers, are his main customers in the international market. Current prices range from $2,800 to $4,000 per gram, but our Tunisian man claims he sells his pure purple dye for less money. Well, considering that it takes 100 kg of murex shell to obtain one single gram of dye, it is not surprising that prices are sky-high.

As mentioned in the book The Macedonian War Machine by David Karunanithy, the final color could vary from rose-pink through bright red and blue to deep purple, depending on the strength of the dye used and its degree of exposure to sunlight. One seashell fits all, right?

It would be great if the wish of Mohamed Ghassen Nouira to have his work exhibited in the Tunisian museums would materialize. I think many other countries, especially around the Mediterranean Sea, should be interested as well. This ancient tradition truly deserves to be kept alive.