Isabella Whitworth

probably more than natural and synthetic dyes, wax, resists, and history

Tyrian Treasure: Part One



writtentyreThe Guardian: Monday 5th December 2016.

‘The shellfish that was one of the main sources of Tyrian purple – one of the most storied and valuable trading products in the ancient world – has disappeared from the eastern Mediterranean coast, amid warnings of an ongoing multi-species collapse blamed on global rises in sea temperatures.’

Historical cessation of shellfish dyeing The word ‘Tyrian’ derives from the city of Tyre on the north African coast, an area long associated with the Phoenicians and the shellfish dyeing industry. Tyrian Purple has already ‘disappeared’ once. Although an article linked from the Guardian states ‘snail-fueled purple persisted until chemists learned to make synthetic dyes,’ this is quite untrue.

It’s well known (in the dye world, at least) that shellfish dyeing largely ceased around the time of the Fall of Constantinople in 1453, after which the last dyers seemed to have disappeared. And in the eastern Mediterranean, purple dyeing ceased almost a millennium earlier as a result of the Arab conquest at the beginning of the 7th century.  Analysis of historic textiles continues to confirm this. The biochemical method of shellfish dyeing was complex, relying on processes which were not understood chemically, and were probably only passed down within families. Basically, when the dyers ‘disappeared’ they took the method with them. Any contemporaneous written records of the dye process are incomplete or ambiguous, and cannot be used to make a vat.

Recovery of the dyeing method Shellfish pigment must first be made soluble, (as with any dye), and this only occurs in alkaline conditions of around pH 8 and higher. An additional requirement for dissolution of the pigment is that it must undergo ‘reduction’. In reduction the pigment’s molecules are converted to a slightly altered, but more soluble, molecular structure. This reduction process is achieved by removing oxygen from the pigment molecules, or by adding hydrogen to them.  The vat turns a yellowy colour and fibre, threads or fabric are introduced. Colour will return to dyed items as they re-oxygenate on removal into the air. Readers who are indigo dyers will be familiar with this process.

The lost dyeing method Until the painstaking work in the 1990s of a retired engineer, the late John Edmonds, the exact method for creating a true shellfish purple reduction vat was lost. (Note that a reduction vat is entirely different from a direct application process performed by smearing the pre-pigment secretions).  Edmonds used his knowledge of woad fermentation to recreate the ancient shellfish dye method. He knew, from the early 20th century work of Paul Friedländer, that shellfish dye was an indigoid and would need a reduction process to work.  Edmonds used shellfish pigment extract for colour, and the rotting flesh of tinned cockles to start the required fermentation.  In subsequent years, chemist Zvi Koren (more about Zvi later) and artist Inge Boesken-Kanold separately explored and perfected more authentic historical procedures for dyeing and painting using shellfish purple.

The purple threads The earliest known historically accurate shellfish dyeings since the 15th century were, until recently, the initial samples produced by Edmonds. But in 2008 I discovered a small envelope containing purple cotton threads in a nineteenth / early twentieth century archive. They were labelled in as having been dyed with ‘the bodies of shellfish’. Could they be genuine?



Zvi Koren In 2011 I wandered around an exhibition in the company of Zvi Koren. Zvi is an internationally known and respected authority on shellfish purple and his lively presentations on the subject make him a unique and entertaining conference speaker. He showed interest in my presentations on orchil research, and we discovered a mutual obsession for appallingly groanworthy puns.

I tentatively mentioned the envelope of shellfish dyed threads I had found.  Zvi was clearly sceptical, as rightly befitted an analytical chemist, and was fairly certain the threads would be fake. He told me that only a scientific analysis, rather than visual inspection, would prove or disprove the claim. In his work, Zvi has analysed archaeological dyeings previously claimed by analysts to be shellfish dyed. Zvi’s precise analyses on these same artefacts showed that the ‘real purple’ was in fact an overdye produced from madder and indigo. He reminded me that prior to the work of Edmonds and others I’d have to go back nearly 600 years to find a true dyeing supported by chemical analysis. Paul Friedländer, who first identified the chemistry of shellfish purple in 1909, left no known samples.  But Zvi’s a good sport and was clearly intrigued. He suggested I send a small sample of the threads to him for analysis at the Edelstein Center for the Analysis of Ancient Artifacts, in Israel. So I did.

The research Zvi has described his astonishment when his analysis found the dyeing to be genuine shellfish purple, and he suggested we write a paper together. The work we undertook mapped a possible scenario for how the dyeing came about, why, and at what date. It involved parallel investigations based on Zvi’s scientific analysis of the threads through photomicrographic images and instrumental chromatography. We also studied classical and biblical texts; 19th century literature; the history of science and scientific connections; and the remarkable Bedford family of Leeds.  Zvi was extremely patient with my lack of chemical knowledge and I continue to be grateful for his clear explanations, and the general good humour which illuminated the science I frequently failed to grasp.

Significance of our research So is this a big deal? We definitely think so. It’s huge!  Firstly, before the Tyrian Purple dyed threads I found, no other dyeings have been confirmed since around the 15th century. That’s of considerable interest to researchers. Additionally, their very existence superbly illustrates the activities, interests and connections of an industrious Leeds family in the late 19th and early 20th century. More of that in Part Two – which will follow in the next fortnight.

If you are interested in knowing more about any aspect of this research please contact me through the blog. 

Thanks Many thanks to colleague and friend Zvi Koren for his knowledge, diligence and support, and for his comments and additions to this and the following blog. And not forgetting the puns.

Links and bibliography

Whitworth and Koren paper published in Ambix. Available from Taylor & Francis Online here.

Ancient shellfish used for purple dye vanishes from eastern Med  Guardian article , December 5th 2016

Related posts  on this blog

Testing Times 1 & 2

Getting to Blue

A Purple Pursuit

French Connections

Reasons to be Stressful

Talking Orchil

Dyes, History, and a Chilly Trip to Yorkshire

Inge Boesken Kanold artist researching and working with shellfish pigment

The Edelstein Center for the Analysis of Ancient Artifacts

John Edmonds’ book: Tyrian or Imperial Purple Dye: The Mystery of Imperial Purple Dye, Historic Dye series no. 7, Little Chalfont, 2000. Published by the author.

Smearing process of dyeing



21 thoughts on “Tyrian Treasure: Part One

  1. Very interesting! I attended a presentation by Marta Turok at 10iss in Oaxaca last year on the decline of the Purpura sea snail in Mexico, traditionally used by the Mixtec to produce a purple dye. The talk was about the conservation of the species rather than the methodology, so I don’t know whether it’s a similar reduction process.

    • That would have been very interesting to hear. The technique used in Oaxaca is actually direct dyeing, not a reduction process, and seems common to several indigenous peoples on the coasts of Central and South America. My copy of Dominique Cardon’s book ‘Natural Dyes’ confirms that the relevant mollusc species will secrete their colouring liquid fairly easily when detached from the rocks. It isn’t necessary to kill the shellfish, which is, of course, good in conservation terms. The decline of the species may be for similar reasons as discussed in the Guardian article – perhaps the Turok presentation explained this? In the smearing process, the textile is rubbed with liquid mucus and fibres or cloth can thus be coloured but the effect can be patchy or mottled as the colour does not penetrate the fibre but rather concentrates on the surface. Zvi was certain that the Leeds Tyrian Purple samples were dyed, not smeared because he could see the evenness of the dyeing in his images. Thank you for raising this interesting point.

      • Thanks for the information Isabella. According to my notes, Marta suggested that the decline in purpura in Mexico was due not to global warming but to a large Japanese company setting up a factory on the coast in the 1980s, getting local fishermen to collect the snails. It is possible to “milk” the snail to remove the dye, but the fishermen, unlike the traditional Mixtec dyers, lacked this expertise so they killed them to get the dye. I found some more information here:

      • Thank you again. I may have heard the story about the Japanese company, but if so had forgotten about it. I recommend the link you added to other readers interested in the history of shellfish purple.

  2. Inspired ” on second thoughts “, Isabella. Such a wonderful story!

  3. Thanks Isabella, that’s really interesting.

  4. Hi Isabella! I think Shiva lingams are remnants of the infrastructure of this wast industry in South East Asia and India. I do believe this because of cultural setting, historical accounts and the functionality of these altars. Would you have a look at them and give me a second opinion? Shiva lingams are suitable in design to produce murex dye?
    Kind regards and thank you, looking forward!

    • I’m afraid I find this a bizarre theory and don’t begin to understand what prompts your enquiry!

      • Hi Isabella, thank you for answering. I just like history, like to read and keep on bumping into references of the dye as a very important, expensive commodity through millenias. I have looked at ancient trade routes, the fabrication process. The trade routes did connect the Middle East with India. The fabrication involved lots of labour, infrastructure.
        The design of the shiva lingams are perfect to bash and separate thousand of shells, ouse out the dye in a dripping tray, where you can dip the fabrics too, there is a channel to drain the liquid. Shiva lingams are acccompanied by holy cows. To transport firewood, get rid of used up shells, I would like to ask, that the urine of the cows might have been used for the process as well as source of potash?
        Shiva, is depicted on his cow with his blue stained skin, one of the simbols of him is a conch. There are the festival of Holi and Dhurga Puja, involving colour, strangely about similar time as optimum harvest time for murex, suggested by Pliny the elder. My bizarre reasoning just go on endlessly… I asked you, because I do not find any references towards it anywhere, that are they suitable in design or not, so I thought that you know more about the process and would be able to tell me that the design of shiva lingams would suit the purpose? Have a look at the very old ones from Harrappa… First I thought that they are some mill, with a missing top peace, then I looked further. What the locals say…
        I just assume, that if it was very rewarding and laborious, involving whole generations and casts of people, there has to be infrastructure, some remnants of the activities in our present culture. So the shiva lingams, mythology surrounding it just fit the bill. Indian culture is fantastic as they deify every aspects of life and preserve heritage in form of worship. Jewish culture and tradition is one of the longest continuous in the region, intertwined with references toward the dye making. (One of the first mention of Hebrews in the middle east SAG.AZ ment breakers of brains and sinews, would make perfect name of murex dyers, describing band of foreign refugees, they had to come from somewhere. The laws, the traditional Thekelet, Mary making blue, its is a long list)
        It was a lucrative trade, driving exploration, starting point of conversation with communities living in regions where murex be found. Sometimes it ment overfishing and ecological disasters, driving commmunities toward new settlements. But it was an omportant driving force.
        Sorry to startle you, I just quite consumed by it by now and frustrated that I could not find anything about it. You know the saying, there is no new under the sun. Thought that you have encountered some scholar who would have had similar recognition as me. As I say, I think this because of the functionality of the design of the shiva lingams and the cultural and symbolical references surrounding it. From my part is just commom sense.
        Thank you again for answering, I will continue my research, might take up a history course in the future if I cannot put the idea to rest…

        Kind regards,


  5. Dear Katalin,

    Thank you for that full explanation of your question. I can see you interest is a sincere one, you have studied the subject and given it a lot of thought. I will try to suggest why I think your theory is unlikely, but please remember that my knowledge sits on the very periphery of this topic and there will be others who would give you a rather more scholarly response.

    Firstly, I know of no Indian textiles analysed showing shellfish purple. (Of course, that doesn’t mean there aren’t or weren’t any).

    Then, to make a useful amount of dye from shellfish you need an incredible number of shells. The amount varies between species. To transport such a number to any inland area would have been impossible (and in the Indian climate, just imagine the smell!). This suggests that in any such Indian industry away from the coast, the shells would have already been cracked open and only the liquor made from the tiny hypobranchial gland transported. Even in itself that would be very smelly and in the Indian heat I am not sure what would happen chemically to the liquid. It might be rendered unusable, but I am not sure on this point. Whatever the case, it would mean there was no need for the lingams that you suggest were used to crack open the shells.

    When researching the paper I co-authored with Professor Koren, he suggested that the Tyrian Purple samples in Leeds, if not dyed in situ at the coast, would have been made from a small amount of dye liquor containing the hypobranchial gland. The whole shell would not have been transported to Leeds.

    Where spoil heaps of shells have been found, it is noted that only the end of the shell has been broken open so that the dye-giving gland can be excised. Again, there is no practical need for the large lingam for breaking the shell.

    As far as I know, the shellfish dye industry (spoil heaps, dye pits etc) has only been traced to areas very near the coast. You will be able to find a lot about this online. The entire process would have been very smelly and probably took place outdoors and away from where people lived. I feel this makes it entirely unsuited to a temple context.

    My knowledge of the Hindu religion is sparse and I don’t know what caste rules might apply to someone working with shellfish in this way. In the South Indian temples I visited recently, where I saw many lingams, Hindu visitors would not even enter the temple if they had eaten fish the same day. In a vegetarian society, shellfish would have counted as meat / fish so you would need to study Hindu practice to understand more of this.

    Theories like yours always intrigue me, even though I don’t agree that your idea has potency. You take an old idea and turn it on its head, which is what creativity is all about.

    Thank you for writing on this topic: I enjoyed looking at the images of lingams and revisiting India in my head!

    Best wishes

  6. Hi Isabella!

    Thank you ever so much, I really am becoming obsessed with the murex trade, it was huge and I do believe that we have to include it in history and culture as a major factor. You are right, whole casts of people were involved, shells wer picked, traded as currency, had to be processed, fabrics had to be provided. The thing is, that the shiva lingams are draged around and reassembled later like at Koti but there are plenty on coastal areas. There is a thousands just outside Angkor Wat, which stranegly started to decline after the abrupt collapse of the trade, switching to vermes kermillo. There is always the cows with them, found an article wich states that it is a good source of potash and used in the dye production. And their hornes and tail is stained ususally. Than there is the case of Soma, it might be a good candidate for murex. The while Abrahamic tradition would make sense, with the smelly offerings, the impotance of mihr and frankincence, you said it, it stunk…Also, if dyed goods are so expensive, murex dyers are too, so it would make sense for dinastys to capture, keep in capture and move around whole populaton of expert murex dyers. Thank you ever so much again for your answer. Here is a picture of one of the lingams, one of my favourite. It has grooves on the bottom to dip/place the yarn in.

    Kind regards!


    • Dear Katalin
      I wish you luck in your enthusiastic pursuit of the shellfish trade. It has always attracted energetic research because of its exotic connections and fabulous cost: at dye conferences this remains true till the present day. Good luck with your purple pursuit!

  7. Than this is a stele, someone dipping wool in there?

  8. Sorty, wrong one:)

  9. There is quite a lot of depiction looking like they dip the yarn in there. 🙂 I know that there is miles of writings about shiva lingams and soma sacrifices, I just think that these Jacobs altarpieces functionally perfect to bash up shells,dip wool in, drain the liquids, and a very practical explanation of the rituals.

    Thank you thousands again!

  10. And sorry for the bad writing, I wobble on public transport, and English is not my first language:) I am very thankful for your comments and will busy myself to track down the moving of shiva lingams, try to assemble a map. I found that the shells survive some times so can be dragged around too, the small ones were smashed, the larger ones agitated to secrete the sap, was thinking that they might grow them as we do now with clam farms. There it is:
    The Purple Murex Dye in Antiquity / Marianne Guckelsberger

    • I understand your writing perfectly: I’m sure it excels my efforts in any other I language I attempt! Thank you for conveying your interest and enthusiasm in this fascinating subject. Best wishes Isabella

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