From 1500BC to 40BC, where were you?

[Cyril Roger Brossard]

related to a topic discussed here.

Cleopatra’s pearls dissolved in vinegar.
By Livius drusus:

There’s a famous story relayed by Pliny the Elder in his Natural History that Cleopatra drank the largest pearls in the world dissolved in vinegar on a bet with Marc Antony.
There were formerly two pearls, the largest that had been ever seen in the whole world: Cleopatra, the last of the queens of Egypt, was in possession of them both, they having come to her by descent from the kings of the East. When Antony had been sated by her, day after day, with the most exquisite banquets, this queenly courtesan, inflated with vanity and disdainful arrogance, affected to treat all this sumptuousness and all these vast preparations with the greatest contempt; upon which Antony enquired what there was that could possibly be added to such extraordinary magnificence.



To this she made answer, that on a single entertainment she would expend ten millions of sesterces. Antony was extremely desirous to learn how that could be done, but looked upon it as a thing quite impossible; and a wager was the result. On the following day, upon which the matter was to be decided, in order that she might not lose the wager, she had an entertainment set before Antony, magnificent in every respect, though no better than his usual repast. Upon this, Antony joked her, and enquired what was the amount expended upon it; to which she made answer that the banquet which he then beheld was only a trifling appendage to the real banquet, and that she alone would consume at the meal to the ascertained value of that amount, she herself would swallow the ten millions of sesterces; and so ordered the second course to be served. In obedience to her instructions, the servants placed before her a single vessel, which was filled with vinegar, a liquid, the sharpness and strength of which is able to dis-solve pearls. At this moment she was wearing in her ears those choicest and most rare and unique productions of Nature; and while Antony was waiting to see what she was going to do, taking one of them from out of her ear, she threw it into the vinegar, and directly it was melted, swallowed it.
It hasn’t been taken terribly seriously by historians because as you can see, Pliny deploys the story more as an illustration of Antony and Cleopatra’s dissipated, luxurious wastefulness than a realistic description. Besides, a basic test of the tall tale fails: if you drop pearls in vinegar, even highly acidic vinegar, they don’t melt. At least not right away like they do in Pliny’s story.
Classicist Prudence Jones of Montclair State University decided to explore the pearls-in-vinegar possibilities. She didn’t discount the story as fiction off the bat, especially since Cleopatra was said by ancient physician Galen to be well-versed in poison lore. She also wrote a book on cosmetics — fragments of which still exist — displaying an extensive knowledge of chemistry.
Jones began experimenting with calcium tablets, then oyster shells in vinegar. Then in a shocking break, a jeweler gave her two 5 frikkin carat pearls to test.
“Experiments reveal that a reaction between pearls and vinegar is quite possible,” concludes the study. Calcium carbonate plus the vinegar’s acetic acid in water produces calcium acetate water and carbon dioxide, for chemistry fans. Jones finds a 5% solution of acetic acid, sold in supermarkets today and well within concentrations produced naturally by fermentation, takes 24 to 36 hours to dissolve a 5-carat pearl.
Boiling the vinegar, or crushing the pearl, or both, greatly speeds up the reaction, perhaps to under 10 minutes. Interestingly, stronger solutions of acetic acid greatly slows down dissolving (the water takes part in the reaction), something that may have hindered folks testing Pliny’s veracity in the past.
So the straight from earring to vinegar then down the hatch process either didn’t happen, or Cleopatra fixed the bet by softening the pearl for a day or two before wearing them at dinner, or she had the vinegar boiled before dropping in the pearls. I could totally see her hustling Marc Antony like that.



Here is the article found in usatoday.com/tech/science.
Cleopatra, fabled final Queen of Egypt, packed a pretty mean pearl cocktail, according to legend.

To win a bet, the story goes, Cleopatra quaffed a vinegar martini made with a dissolved pearl, "the largest in the whole of history," according to an ancient scribe. Doubted by scholars for centuries, Cleopatra's canny chemistry trick may have actually come off, suggests one researcher, based on her own experiments.
"There's usually a kernel of truth in these stories," says classicist Prudence Jones of Montclair (N.J.) State University. "I always prefer to give ancient sources the benefit of the doubt and not assume that something that sounds far-fetched is just fiction."
In the current Classical World journal, Jones details the history of the story. In it, Cleopatra won a wager with her befuddled Roman consort, Marc Antony, by consuming her pearl cocktail to create the costliest catering bill ever. Her 10 million sesterces (sesterces were the nickels of the ancient world) banquet bill, thanks to the destruction of the pearl, set a pretty early mark on extravagant consumption.
The famous snake-venom suicide of Cleopatra Vll, last ruler of the Egypt's Ptolemy dynasty, in 30 B.C., might suggest she was a fairly tough-minded ruler. Galen, the ancient physician, also suggested she knew her way around poisons and medicines. So why not chemistry, Jones asks.
"I think there was a fairly good understanding of practical chemistry in the ancient world," Jones says, by email. Fertilizer recipes and preparations to kill parasites on sheep appear, for example, in ancient Roman texts.
Pearls were a popular adornment for the wealthy in the Roman era. Because in antiquity the only pearls in existence were natural ones, they were considerably rarer than they are today, making dissolving one a truly wasteful act. "I think modern scholars dismiss the story more out of disbelief," Jones says, noting a long line of references, such as a 1940 translation of the story, for instance, that says, "no such vinegar exists."
The classicist B.L. Ullman of the University of North Carolina noted in 1957 that some experiments suggested that vinegar could indeed dissolve pearls, made of acid-unfriendly calcium carbonate by oysters. But the news never made it to most classicists, says Jones, author of Cleopatra: Life & Times. So, "I began to wonder if there was any truth behind it and started trying some experiments, at first with calcium supplement tablets and pieces of oyster shell and then with pearls," she says.
To experiment with large pearls, Jones found a jeweler who had a couple of 5 carat ones that had been removed from pieces of jewelry. "They were not perfectly round and so were not suitable for other settings and were going to be disposed of," Jones says. "He was willing to donate these to my experiment."
So what did she find? "Experiments reveal that a reaction between pearls and vinegar is quite possible," concludes the study. Calcium carbonate plus the vinegar's acetic acid in water produces calcium acetate water and carbon dioxide, for chemistry fans. Jones finds a 5% solution of acetic acid, sold in supermarkets today and well within concentrations produced naturally by fermentation, takes 24 to 36 hours to dissolve a 5-carat pearl.
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[Cyril Roger Brossard]

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Boiling the vinegar, or crushing the pearl, or both, greatly speeds up the reaction, perhaps to under 10 minutes. Interestingly, stronger solutions of acetic acid greatly slows down dissolving (the water takes part in the reaction), something that may have hindered folks testing Pliny's veracity in the past.
"Currently, when I do the demonstration for people, I use small cultured pearls from a bracelet I purchased at K-Mart for $20," Jones says.
Biochemist Takeshi Furuhashi of Austria's University of Vienna tried his own experiments with nacre shells from Red Sea oysters to see if he could reproduce Jones's results for USA TODAY. He finds that without boiling or crushing the pearl, many hours would be needed for the acid to dissolve a large pearl. But at low concentrations of acetic acid, he reports, only an hour was required to dissolve a crushed pearl shell. So, if Cleopatra crushed the pearl, the story may be true, Furuhashi says. "However, if she put her earring directly into solution, it is impossible to obtain the same results."
She may also have soaked the pearl in vinegar for a day or two to soften it up, he adds. Indeed, Jones says other stories about ancient wastrels knocking back pearl boilermakers involve prepared vinegar and pearl solutions being brought to the banquet table.
"I think the most likely explanations for the discrepancy between the experiment and the (legend) Pliny describes, during a banquet, are that the story compresses events for dramatic effect," Jones says, "or that Cleopatra drank the cocktail with the pearl only partially disintegrated, having satisfied her guests that it was destroyed."
And there is always the chance, Furuhashi suggests, that she just palmed the pearl and duped Antony. Cleopatra was no fool, after all, and as the Cleopatra: the Search for the last Queen of Egypt exhibition now at Philadelphia's Franklin Institute shows, her family had ruled one of the centers of the civilized world for centuries before the Romans arrived.
"Ancient peoples had a lot of practical scientific knowledge," Jones says. From mummification to poisons, to Cleopatra and the pearl, the ancients knew their way around the medicine chest. "While the reaction between a vinegar and a pearl might not have been called an acid-base reaction, there was a practical understanding that some substances could destroy others," says Jones.



Now based on the above, I conjectured two possible source of pearls the first is considering that the countries of the Arabian Gulf are endowed with pearl oyster resources that have been exploited for natural pearls from time immemorial, and they have depended on these marine economic resources. Egyptian women had pearls in their jewellery as early as 1,500 B.C. and the early Arabian geographer Massoudi noted the existence of Gulf pearls in the 9th century (SHARABATI 1981). As early as the 3rd century B.C., Nearchus reported that, in the Red Sea, pearls occur most extensively around the Dahlak and the Farasan Islands in the southern part of the Red Sea (SHARABATI 1981). (Torsten Wronski, 2010)
Then, in 1500BC, Egypt already had a blooming trade with Afghanistan, Pakistan and the Indus Valley Civilization, could it be that early Egyptian women wore pearls issued from trade with India?

The second possible source is that the pearls in question (40BC) originated from the Red sea, that is from natural seabed of either Pinctada radiata or from Pinctada margaritifera (Linnaeus, 1758), (also referred to as Meleagrina margaritifera or Pteria margaritifera). (Hasan, 1974 and 1983) (AL-KHAYAT & AL-ANSI 2008).
References to Alexandria being suitable for this species tend to confirm the above.
The distribution of the population shows that Pinctada radiata represent 95% of the natural population with a distinct predominance from shallower water than Pinctada margaritifera. The later shares the deeper water with Pteria aegyptiaca (Dillwyn, 1817). I do not know how deep could divers go 40BC but logic tends to point to pearl produced by Pinctada radiata, but again this is a conjecture...
It seems as well that the Farasan islands are predisposed as a perfect biome for the pearl producing species above mentioned. Descriptions make mention of high salinity, constant temperature and presence of Avicennia spp. or Rhizophora spp., mean to say fast growth rate expected...