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Royal / Imperial Purple Dye (Ancient Rarity Obtained From Molluscs)

Yithian

Yithian

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Supermarket molluscs reveal Roman secret

By Kristine Krug, in Salford

The secret of imperial purple has been rediscovered.

A British amateur chemist has worked out how the ancient Romans dyed the togas of emperors this deep colour thanks to a bacterium found in cockles from the supermarket Tesco.

The hue had special significance as the colour of imperial power. Cleopatra also had the sails on her ship dyed the same colour.

The recipe for the dye had been kept a craft secret, even in ancient Egypt and Rome. There are few references to the dying process in the historical literature.

Green to purple

Modern chemistry can make every shade of every colour, but retired engineer John Edmonds is interested in how the ancients managed to make dyes from natural materials.

He explained to the British Association science festival in Salford, Greater Manchester, how he rediscovered the secret of imperial purple after studying the fermentation process of indigo pigments from the woad plant.

With help of researchers in Reading and from Israel he has been able to establish the vital role played by a bacterium in chemically reducing (the addition of electrons) the ancient pigments so that they will dissolve in a dye solution.

The pigment for imperial purple was derived from Murex molluscs, a form of shellfish. So, Mr Edmunds reasoned that he could try to use the related common cockle.

He bought a jar of them from Tesco. "Having removed the vinegar, I placed several of the cockles with some of the purple pigment in a vat consisting of a 2 lb jam jar."

Modern jeans

The cockles are thought to harbour a bacterium that is crucial in reducing the dye. Wood ash was added to the vat to ensure the mixture did not turn acidic.

The mixture was then kept at 50 Celsius for about 10 days.

Wool dipped in the pigment turned green at first but, eventually, in contact with light, it turned purple.

The recreation of the old dying method might have implications for present-day practice.

Currently, tonnes of chemicals are needed to reduce the dye for denim blue jeans, resulting in large quantities of sulphur waste.

Mr Edmonds said: "University of Reading scientists are trying to understand how the bacterium reduces indigo in order to develop a clean biotechnology to replace the chemical process for indigo reduction in the future." http://news.bbc.co.uk/1/hi/sci/tech/3103354.stm
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Also, it's heartening to see the discovery made by a keen amateur.
 
A British amateur chemist has worked out how the ancient Romans dyed the togas of emperors this deep colour thanks to a bacterium found in cockles from the supermarket Tesco.
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I had no idea Tesco's had been around that long. :rolleyes:

Big Bill Robinson
 
i wonder when he'll get bought-out, after patenting his discovery, by a big chemical firm?
 
A little background to add to your interesting story Y.

Indigo,an important and valuable vat dyestuff, obtained until about 1900 entirely from plants of the genera Indigofera and Isatis. Indigo was known to the ancients of Asia, Egypt, Greece, Rome, Britain, and Peru. It is used in the United States mainly for dyeing cotton for work clothes; for a long time it was used to produce heavy (navy blue) shades on wool.
The naturally occurring precursor of indigo is indican, a colourless, water-soluble substance that is easily hydrolyzed to glucose and indoxyl; the latter is converted to indigo by mild oxidation, such as exposure to air.
The chemical structure of indigo was announced in 1883 by Adolf von Baeyer; a commercially feasible manufacturing process was in use by the late 1890s. The method, still in use throughout the world, consists of a synthesis of indoxyl by fusion of sodium phenylglycinate in a mixture of caustic soda and sodamide.
Indigo can be converted to numerous simpler compounds, but the only chemical reaction of practical importance is its reduction to the soluble yellow leucoindigo, in which form it is applied to textile fibres and reoxidized to indigo.
Tyrian purple, a dyestuff of great importance in antiquity, was obtained from a secretion of a sea snail (Murex brandaris) common in the Mediterranean. Its structure is very similar to that of indigo. It has never been produced synthetically on a commercial basis.
 
p.younger said:
Tyrian purple, a dyestuff of great importance in antiquity, was obtained from a secretion of a sea snail (Murex brandaris) common in the Mediterranean. Its structure is very similar to that of indigo. It has never been produced synthetically on a commercial basis.
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I love odd things like this especially when they pose the question how on earth were such discoveries originally made?

I can only assume serendipidy, which is a strangely pleasing thought.
 
~runs in, realises that The Secret isn't out and casually walks away whistling~
 
Yithian said:
I love odd things like this especially when they pose the question how on earth were such discoveries originally made?

I can only assume serendipidy, which is a strangely pleasing thought.
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Sometimes the snails get caught in rock pools and die (or should that be dye?). As they decay, the warm water is stained reddish, and over time darkens to the royal purple. This still happens today in the Medditerranean. It would only have been a matter of time before locals, seeing the pretty colours, tried dipping their clothes in the pools.

So this particular case was just people following nature's lead. But I know what you mean, how on earth would anyone invent gunpowder?
 
Si Fuller said:
Sometimes the snails get caught in rock pools and die (or should that be dye?). As they decay, the warm water is stained reddish, and over time darkens to the royal purple.
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Brilliant, thanks for the explanation. Now added to my formidable arsenal of 'did you know?'/ 'bore 'em to death at parties' facts.

In keeping with my warm outlook on such things, this strange process leads one to reflect cheerfully that either:

a) it is a wonderfully complex universe 'where the curious adaption of means to ends' suggests more than just chance is at work

Or:

b) Man is so wonderfully inventive and opportunistic that he can make anywhere his own home and always rustle up a means to his peculiarly human ends.
 
I think this story of ancient dyes and a bit more history fits in here.

3,000-year-old textiles are earliest evidence of chemical dyeing in the Levant
Discovery provides insight into society and copper production in the Timna region at the time of David and Solomon, researchers say
Date:
June 28, 2017
Source:
American Friends of Tel Aviv University
Summary:
Archaeologists have revealed that cloth samples found in the Israeli desert present the earliest evidence of plant-based textile dyeing in the region. They are estimated to date from the 13th-10th centuries BCE, the era of David and Solomon.

https://www.sciencedaily.com/releases/2017/06/170628144843.htm
 
The ancient trade in royal purple dye is often associated with the Phoenician city of Tyre. Recent excavations on Chrysi (an island near Crete) have discovered what seems to be a Minoan industrial complex dedicated to producing the dye. The site exhibits evidence that the Minoans were able to "farm" the Murex molluscs in artificial enclosures.

Gold and Jewels Found on Minoan Island Devoted to the Color Purple

A storehouse of ancient treasures, including precious jewels and gold beads, has been uncovered by archaeologists on an island near Crete devoted to making a precious purple dye from sea snails thousands of years ago.

The finds on Chrysi — a now uninhabited island — show the high value placed on the rare purple dye and the flourishing economy of the settlement between 3,800 and 3,500 years ago, during the Protopalatial and Neopalatial periods of the Minoan civilization on Crete. ...

The purple dye produced from Murex sea snails was a precious rarity in the Bronze Age Mediterranean region, explained bioarchaeologist Deborah Ruscillo of Washington University in St. Louis, Missouri.

Ruscillo has studied the production of the ancient purple dye, including experimenting with it to make colors from pink to blue to almost black, though she isn't involved in the excavations on Chrysi.

"Purple did not exist from any other source at the time," she told Live Science. "Cheaper plant substitutes, such as madder or woad, did not come around until the Middle Ages, so until that time Murex purple was the only source."

The shellfish make a small amount of the purple substance inside their bodies, and use it as a poisonous defense against predators. ...

It takes thousands of Murex sea snails to produce enough purple dye to color a single garment, a difficult and sometimes dangerous task. "There was danger and discomfort involved in harvesting the snails from the sea, strength required to break open the shells, [and] the smell was horrendous," she said.

The difficulty of making the dye led to it only being used by the wealthy and royal, and it became known as "Royal purple."

It was also known as "Tyrian purple," after the ancient Phoenican coastal city of Tyre, a source of the dye; and it's thought to be the Tekhelet dye described in Hebrew scriptures as the color of the curtains of the tabernacle and the vestments of the high priest, Ruscillo said. ...
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FULL STORY: https://www.livescience.com/gold-jewels-found-on-island-purple.html
 
Another ancient purple pigment rescued from the mists of time.

Scientists have resurrected a purple-blue hue whose botanical origin had been lost to time.

The pigment, called folium, graced the pages of medieval manuscripts. But it fell out of use, and the watercolor’s identity has eluded scientists for decades. Now, after tracking down folium’s source, researchers have mapped out the chemical structure for its blue-producing molecule.

Such chemical information can be key to art conservation. “We want to mimic these ancient colors to know how to … preserve them,” says Maria Melo, a conservation scientist at Universidade Nova de Lisboa in Caparica, Portugal. But to unmask folium’s identity, Melo and her team first had to find where it came from.

The researchers turned to medieval texts that described the source plant. With the help of a botanist, they discovered Chrozophora tinctoria, a tiny herb with silvery-green foliage. In a village in the south of Portugal, the team found the wild plant growing along the roadside and in fields after harvest. Back in the lab, researchers extracted the pigment from its pebble-sized fruits by following directions detailed in the medieval manuscripts. “It was really great fun to recover these recipes,” Melo says.

https://www.sciencenews.org/article/ancient-recipes-medieval-pigment-natural-blue
 
Oh!

The Romans used Dog whelks in this country.

But you need vast amounts to make your dye. (colourfast, and so incredibly valuable in a world in which all dyes are water based)

And its a nasty smelly process
 
ramonmercado said:
Another ancient purple pigment rescued from the mists of time.

Scientists have resurrected a purple-blue hue whose botanical origin had been lost to time.

The pigment, called folium, graced the pages of medieval manuscripts. But it fell out of use, and the watercolor’s identity has eluded scientists for decades. Now, after tracking down folium’s source, researchers have mapped out the chemical structure for its blue-producing molecule.

Such chemical information can be key to art conservation. “We want to mimic these ancient colors to know how to … preserve them,” says Maria Melo, a conservation scientist at Universidade Nova de Lisboa in Caparica, Portugal. But to unmask folium’s identity, Melo and her team first had to find where it came from.

The researchers turned to medieval texts that described the source plant. With the help of a botanist, they discovered Chrozophora tinctoria, a tiny herb with silvery-green foliage. In a village in the south of Portugal, the team found the wild plant growing along the roadside and in fields after harvest. Back in the lab, researchers extracted the pigment from its pebble-sized fruits by following directions detailed in the medieval manuscripts. “It was really great fun to recover these recipes,” Melo says.

https://www.sciencenews.org/article/ancient-recipes-medieval-pigment-natural-blue
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Thanks for posting this! I had no idea.

I grow woad, madder, bedstraw and usually find weld on abandoned garage fore courts or grass verges... recreating colours is great fun. Slugs usually get my woad these days but if I get enough I use the “ancient method” pioneered and rediscovered by Jill Goodwin, back in the 40s or 50s, to make blues (ie: ferment with men’s wee as it works better for some reason).

I wonder if there was a Poor Man’s purple where blue was overdyed with red? Have never tried it but maybe this summer is the year those experiments get done...
 
I wonder if there was a Poor Man’s purple where blue was overdyed with red? Have never tried it but maybe this summer is the year those experiments get done...
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Make sure that aren't any covenants applied to your home before hand etc.
 
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