Shellfish purple

Andreotti A, Bonaduce I, Colombini MP, Ribechini E (2004) Characterisation of Natural Indigo and Shellfish Purple by Mass Spectrometric Techniques. Rapid Commun Mass Spectrom 18 1213... 

We examined first the archaeological materials for dyestuflF identification at the request of Junius Bird of the American Museum of Natural History on behalf of Peter Gerhard who was studying the distribution of the shellfish purple dye. This dye is believed to have been used in ancient times in Central and South America and in Mexico and is still in use on the west coast of Mexico. The results of his work have been published 11), and we will confine our comments to the analytical... 

Figure 2, Known shellfish purple dye solutions compared with those obtained...

Figure 4. H SO (cone,) solutions of indigo (----) and shellfish (----) purple dye...

An excellent example of the value of this information comes from our recent examination of a collection of native Mexican materials which were made by the Mixtec Indians of southwest Mexico. While we had examined samples of purple yarns from this region (shellfish purple is still gathered and used in this area), we had never looked at any red yarns. Cochineal is native to Mexico and this area is cochineal country. We examined 23 samples which were generally believed to be cochineal. 

On the other hand, the almost colorless fluid secreted by Murex brandaris, a shellfish of the Mediterranean Sea region, becomes reddish purple on contact with air. The fluid was used by the Phoenicians as a dye from about 1500 BC, and the purple dye is known as Tyrian purple, ancient purple, or shellfish purple, etc. Friedlander, in 1915, isolated about 1.5 g of the pigment from 12,000 specimens of M. brandaris, and clarified its chemical structure as 6,6 -dibromoindigo [5]. Subsequently, the origin of this pigment was identified as sodium tyrindoxyl sulfate [6]. 

During excavations carried out on the island of Zembra in Tunisia, a purple clay earth was discovered in a stratigraphic layer dating back to the third century BC. Karmous et al. have made various studies of what they term Zembra punic purple or purple earth from Zembra and shown it to be a shellfish purple... 

Textile dyes were, until the nineteenth century invention of aniline dyes, derived from biological sources plants or animals, eg, insects or, as in the case of the highly prized classical dyestuff Tyrian purple, a shellfish. Some of these natural dyes are so-caUed vat dyes, eg, indigo and Tyrian purple, in which a chemical modification after binding to the fiber results in the intended color. Some others are direct dyes, eg, walnut sheU and safflower, that can be apphed directly to the fiber. The majority, however, are mordant dyes a metal salt precipitated onto the fiber facUitates the binding of the dyestuff Aluminum, iron, and tin salts ate the most common historical mordants. The color of the dyed textile depends on the mordant used for example, cochineal is crimson when mordanted with aluminum, purple with iron, and scarlet with tin (see Dyes AND DYE INTERMEDIATES). 

The ostrum of Vitruvius, a beautiful and costly purple color, was obtained from certain marine shell fish. It varies in shade according to the regions where found, being black in the north, as Pontus and Gaul, red in the south as at Rhodes, and blue or violet in the intermediate regions. The shellfish are collected and broken with iron tools, and the purple fluid exudes. On account of its saltness, it soon dries up unless honey is added to it. Large quanti-... 

Compounds of bromine had been known for hundreds of years before the element was discovered. One of the most famous of these compounds was Tyrian purple, also called royal purple. (Tyrian comes from the word Tyre, an ancient Phoenician city.) Only very rich people or royalty could afford to buy fabric dyed with Tyrian purple. It was obtained from a mol-lusk (shellfish) found on the shores of the Mediterranean Sea (a large body of water bordered by Europe, Asia, and Africa). 

It is one thing to discover a coloured substance but its attachment, in a fast or permanent condition, to a fabric is a different and often difficult matter. That the ancient dyers had attained a complete mastery of the art of dyeing with Tyrian Purple is clear from the assertion of Lucretius in De Rerum Jiaiura The purple dye of the shellfish so unites with the body of wool alone, that it cannot in any case be severed, not were you to take pains to undo what is done with Neptune s wave, not if the whole sea were willed to wash it out with all its waters. ... 

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