International Exposition of Paris 1867

Agriculture, Industry and Fine Arts

April 1, 1867 - November 3, 1867


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Diamond cutting

Diamond cutting at the Exhibition Paris 1867

The Exhibition of 1867 will provide us with the opportunity to give some details of a very special nature on the exploitation and handling of this precious stone, whose name alone sparks all the desires of luxury, and awakens in the imagination the fantastic tales of the Thousand and One Nights.

We shall therefore confine ourselves today to giving, on the occasion of the diamond cutter of which our engraving represents the exterior, some interesting particulars on this element so rare and so appreciated in our modern jewellery.

The scientists who are accustomed to say the name of things, have simply found in the diamond crystallized coal.

This way of coldly considering this focus of luminous rays that man attaches to his most pompous ornaments, while perfectly accurate, is no less infinitely unpoetic, and puts us far from the point of view of Patin, another scientist too, who wanted the diamond to be a concretion of luminous matter, just as coal was for him only fixed fire.

In its rough state, diamond is usually rough on its surface and slightly translucent.

For a long time, its real value could not be determined. In Pliny's time, it was only recently appreciated, at least that is what we can conclude from the way he expresses himself on the subject.

However, some diamonds, even in their natural state, had such a bright sparkle that attention was drawn to them, and ladies, as well as great lords, natures easily captivated by what glitters, made them ornaments and marks of distinction. In the fourteenth century, the King of Portugal owned one almost as big as an egg and wore it proudly, rough and shapeless, on his hat on great feast days.

It was only towards the end of 1470 that the important discovery of cutting and polishing diamonds and giving them the facets that make them so magnificent was made.

Like all inventions, this one has its legend.

Here is what is reported about it:
The Count of Charolais, who later became the fierce Charles the Bold, had a very pronounced liking for precious stones, and had quite a nice collection of them.

A diamond of remarkable size was especially the object of his predilection.

This diamond, which is none other than the Sancy, whose name has become famous, was without form and almost without brilliance.

The prince, who was then at the court of his father Philip the Good, at Bruges, made a great number of attempts to give his precious jewel all the brilliance it could contain, when a young man, a jeweller, whose descendants practised the same profession in Paris under Henry III, named Louis de Berquen, came to suppose that, since the hardest steel was impotent to cut through the diamond, he could try as a back resource to oppose to the rough stone, the friction and hardness of the stone itself.

He tried it; it succeeded. The art of cutting diamonds was found.

Dazzled by his success, Louis de Berquen communicated it to Charles, and obtained the favour of cutting his large diamond, which, as I said, was to be called the Sancy. A new success, a brilliant success this time, crowned his work, and earned him a reward of three thousand ducats.

Louis de Berquen kept his secret at first and in a short time became immensely rich.

The chronicle, in turn, took hold of the young and famous jeweller and portrayed him as poor, in love with the daughter of a rich jeweller who, being stingy and proud, only wanted (as in the nineteenth century) to give his daughter in marriage to a man who had gold.

To this end, Louis de Berquen would have directed his research into the secret of diamond-cutting, having often heard the father of the woman he loved say that he would become opulent if he discovered this difficult art. All his efforts had failed at first. At a certain point he finally learned that his fiancée was going to be given to another man. This news surprised him in the midst of his labours, and in anger he is said to have violently crumpled between his hands two diamonds on which he was experimenting. A small dust escaped; the diamonds retained the traces of the violent rubbing he had made them undergo, and he was able to exclaim like Archimedes: Eureka!


The Sancy has had many adventures.

Found by a soldier on the corpse of Charles the Bold killed in Nancy in January 1477, it was sold for one ecu to a priest, who was as ignorant as the soldier.

A merchant bought it for three ducats from the priest, and sold it for twelve to the Duke of Florence. From there it passed into the hands of the King of Portugal, Don Antonio, who disposed of it in France where he had taken refuge.

Nicolas de Harlay, Sieur de Sancy, paid 70,000 fr. for it, and since that time the name of Sancy has remained attached to the precious diamond.

Henry IV, embarrassed in his finances, tried to sell it to the Swiss, through the intermediary of a faithful servant, who was attacked by thieves, swallowed the diamond and died without being robbed. The diamond was found in the body of this brave and faithful servant.

It was then that Henry III pawned the Sancy with the Jews of the city of Metz. Here we lose track of his adventures and we only find it again under Louis XIV who bought it for 600,000 francs: he wore it in his crown on the day of his coronation. The Sancy remained in the possession of the House of France until Louis XVIII, then it disappeared again; and in 1830 it was found to belong to the Prince of Peace.

Since Louis de Berquen the art of diamond cutting has made immense progress, and as we said above we shall have occasion to return to the processes and mechanisms employed today.


As a general thesis, here is how it is done:

One begins by roughening it by rubbing two rough diamonds one against the other: a very fine powder is detached from it which is collected with the greatest care.

The rough shape is then sealed with tin in a copper shell held in a steel pincer. The diamond thus mounted is then subjected to a circular friction, due to a very rapid rotational movement imparted to a mild steel platform on which diamond dust and olive oil have been previously spread.

Wear occurs on each of the faces presented to the platform, and the gemstone is finally cut and polished completely.

Diamond deposits are rare, extremely difficult to mine and therefore expensive. The main ones are found in India, in the Dekan, and particularly in the valleys of the Pannar and Krichna rivers; on the island of Borneo, in Brazil, and finally since 1829 in Siberia.

The diamond is generally scattered and in small quantities: frequently it is wrapped in a rather adherent earthy film which requires washing, and it is only after this washing that it can be more easily recognised.

The quantity of diamonds supplied annually to the trade by Brazil does not amount to more than about 6 to 7 kilograms, in volume two litres. This quantity, which is almost the total representation of the diamond trade movement, requires an annual sum of more than one million in operating costs.

Diamonds found to be defective still sell for 156 francs per gram or about 12 francs per karat, which is equivalent to 212 milligrams.

Up to 50 milligrams, the figure we have just indicated increases uniformly; but above that the proportion is much more considerable; for a rough diamond weighing one gram, that is to say approximately five karats, is worth one thousand francs, and a cut diamond of the same weight arrives at 3500 fr.

Let us give, in conclusion, the nomenclature of the most famous diamonds by their size and their shaping.
Here they are in order of weight:
That of Agrah, weighing about......133pr.
That of the rajah of Mattan, in Borneo. ... 78
That of the former emperor of Mogol. . 63
That of the emperor of Russia.......41
That of the Emperor of Austria...... 29 53
That of the King of France, called the Regent. 29 89

A simple calculation can establish the figure of the fabulous sums reached by these precious stones, which, by their very value, are safe from theft; however, if the progression of luxury and commercial transactions still follows the same upward march, it would not be surprising if diamonds were to become the high currency of the future, especially since the engraving of this precious stone has been made possible by Claude Briagues. Fortunes would then be more easily transportable; and if, as Lessing says, "a drop of sun dew is as beautiful and costs less," it is no less true that it is impossible to store the dew and the sunbeam that makes it glow, whereas one can always store the diamond.

©L'Exposition Universelle de 1867 Illustrée