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Thursday, April 17, 2008

The Great Florentine Diamond—A Fancy Sancy Cut

(via Diamond Cuts in Historic Jewelry:1381-1910) Herbert Tillander writes:

The Great Florentine diamond (fashioned in 1615) has several names. It has been called the Tuscan, the Tuscany Diamond, the Grand Duke of Tuscany, and even the Austrian Yellow Diamond—an unfortunate name, since it creates confusion with another lost diamond, the Austrian Yellow Brilliant.

The stone was drop-shaped with both the front and the reverse more or less similarly faceted. The center of the front had trihedral faceting, but the mactching area on the reverse simply had nine basic facets. Both front and reverse were stepped twice, producing nine rows, each containing nine facets in the front, and seven rows of nine facets on the reverse—144 facets in all. The overall impression is of a nine-rayed star.

Through the works of Speranza Cavenago Bignami, Guido Gregorietti and others, I have been able to trace the history of this stone. P.Aloisi stated in 1932 that the rough stone was ‘acquired’ in the late sixteenth century from the King of Vijayanagar (modern Narsingha) in southern India by the Portuguese Governor of Goa, Ludovico Castro, Count of Montesanto, after the king’s defeat by Portuguese troops. The crystal was deposited with the Jesuits in Rome until, after lengthy negotiations, Grand Duke Ferdinand I of Tuscany succeeded in buying it from the Castro-Noranha family for 35000 Portuguese scudi crocati.

Duke Ferdinand’s son, Grand Duke Cosimo II (who ruled from 1609 to 1621), finally entrusted his father’s purchase to a cutter, Pompeo Studentoli, a Venetian working in Florence. The finished gem was delivered on 10 October 1615. An inventory drawn up on Cosimo’s death confirms the acquisition of the rough diamond by Ferdinand and describes the gem as ‘faceted on both sides and encircled by a diamond-encrusted gold band.’

Dr Heinz Biehn reproduced a sketch of a pendant containing the Great Florentine with a caption reading, ‘Il Gran Diamante del Serimo Gran Duca di Toschana , Pesa 138 Carati.’ Despite extensive investigation, the origin of this drawing remains obscure. The correct weight and the exact faceting indicate that it was probably drawn just after its fashioning in 1615. The outline differs slightly, most likely because the artist wished to show a perfect and therefore pleasing symmetry.

Thomas Cletscher, who must have seen the gem in Florence, produced a clearly recognizable sketch of it in about 1625: neither the faceting nor the outline is aboslutely correct, which indicates that it may have been done from memory. The faceting of the central trihedrally faceted section is fairly accurate, but the surrounding steps, which he depicts as being similarly fashioned, cannot be correct. Cletscher also gives the weights of the rough and the finished gem as being 170 ct and 120 ct, neither of which would appear to be accurate.

The next specialist to describe and sketch the diamond was Tavernier, who claims to have seen it in 1657 and on some other occasion. The outline he gives differs from the actual shape of the stone, although he reproduces the faceting correctly; but he gives faceting of the reverse of the gem with its six basic facets in the centre, instead of the trihedral faceting of the front. Max Bauer gives more plausible proportions. Other authors have either reproduced these same illustrations or drawn from their imaginations.

My own line drawing are based on the only available photograph, but this is so poor that the faceting cannot be clearly seen. The correct girdle outline is, however, found. As to the design, I have studied the sketches carefully and am convinced that this is how the faceting must have been. At first glance it looks as though the gem was almost symmetrical, but in fact this was not so. The drawings show the actual shape of the stone and a symmetrized version.

Little is known of the jewel once it was set. No doubt it remained in the Medici family ans was worn occasionally, even though there are no portraits in which it appears. It was mentioned in an inventory of 1740, after the death in 1737 of Giovanni Gasto, husband of Duchess Anna Maria. The jewel remained in her possession until her death without heirs three years later, when it became part of the Tuscan duchy treasury.

Meanwhile, in 1736, Francis Stephen, Duke of Lorraine, had been obliged to renounce his duchy because of his marriage to Maria Theresa of Austria, but had been given Tuscany instead. In 1747 he became Holy Roman Emperor and he took the Florentine diamond to Austria as one of his own personal possessions. It was set, first in a crown and then in a hat jewel. When the Austrian empire came to an end in 1918 the jewel was removed from the treasury by the ex-Emperor Karl, and disappeared.

Surprisingly little has been written about the Florentine, perhaps because it was in a private treasury and not easily available for inspection. The only known analysis was by Schrauf, who gave its weight as 27.454 grams (i.e. 137.27 ct). J Cohn, basing his statements on undisclosed sources, said that the Florentine was of a light greyish-yellow color and displayed quite exceptional dispersion (fire), which strengthened this color. He added that it was flawless and of a good make and, taking all factors into consideration, classified it as being of ‘second water.’

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