The Florentine Diamond is one of the most celebrated and enigmatic stones in the history of gemmology — a large yellow diamond of 137.27 carats, cut in the distinctive double rose form with 126 facets, that passed through the hands of some of Europe's most powerful dynasties before vanishing from the historical record in the aftermath of the First World War. Also known as the Tuscany Diamond and, in older literature, simply as the Florentine, it ranks among the great lost diamonds of the world, alongside the Sancy in its earlier wanderings and the Orlov in the complexity of its provenance. Unlike those stones, however, the Florentine has never resurfaced.

Physical Description

The stone's weight of 137.27 carats places it firmly among the historically significant large diamonds. Its colour has been described in period sources as pale yellow, sometimes with a greenish cast — a description consistent with a Type Ia or possibly Type IIb stone, though no modern spectroscopic analysis has ever been performed on a specimen confirmed to be the Florentine. The double rose cut — essentially two rose-cut crowns placed base to base, producing a lens-shaped or cushion-like outline — was a fashionable form in the sixteenth and seventeenth centuries, particularly for stones of exceptional size where the cutter wished to retain maximum weight. With 126 facets arranged across both hemispheres, the Florentine would have displayed a lively, if somewhat shallow, play of light characteristic of the rose-cut family. No modern brilliant or step-cut reworking is documented.

Provenance and Early History

The early history of the Florentine is entangled with legend and competing attribution, and the scholarly consensus is that several distinct stones may have been conflated in early accounts. The diamond is most reliably traced to the Medici collection in Florence, where it appears in inventories of the late seventeenth century under the care of the Grand Duchy of Tuscany. Cosimo III de' Medici is among the rulers associated with its custody. When the Medici line died out in 1737, the Grand Duchy passed to Francis Stephen of Lorraine, who subsequently became Holy Roman Emperor Francis I, consort of Empress Maria Theresa. The diamond thus entered the Habsburg treasury in Vienna, where it was incorporated into the Austrian imperial regalia and remained for nearly two centuries.

Earlier attributions — connecting the stone to Charles the Bold of Burgundy, who lost a great yellow diamond at the Battle of Grandson in 1476, or to the Portuguese crown — are not supported by a continuous documentary chain and are now generally regarded as speculative. The Burgundian diamond and the Florentine may well have been entirely separate stones.

The Habsburg Period

Within the Habsburg imperial collection, the Florentine was among the most prized objects in the Schatzkammer (Imperial Treasury) in Vienna. It was set at various times in jewelled orders and ceremonial pieces, and its pale yellow colour distinguished it visually from the colourless diamonds that dominated European court jewellery of the eighteenth and nineteenth centuries. Detailed descriptions survive from the nineteenth century, and the stone was examined and documented by several European gemmologists and court jewellers, providing the most reliable physical data available. Its weight of 137.27 carats is the figure most consistently cited in these records.

Disappearance

The collapse of the Austro-Hungarian Empire at the end of the First World War in 1918 precipitated the dispersal of the Habsburg imperial treasures. Emperor Karl I went into exile, and the imperial family took a portion of the crown jewels with them. The Florentine Diamond was among the items removed from Vienna. According to accounts that have circulated in gemmological and historical literature, the stone was taken to Switzerland and subsequently to South America — Argentina is the country most frequently named — by members of the Habsburg family or their agents. At some point in this journey, it is believed to have been recut, which would have destroyed its distinctive double rose form and rendered it effectively unidentifiable among the world's large yellow diamonds. No stone has ever been confirmed as the recut Florentine.

The Austrian government has periodically asserted that the removal of the imperial jewels constituted a breach of the post-war settlement, and the Florentine's disappearance has been the subject of legal and historical inquiry. No recovery has been made.

Significance in Gemmological History

The Florentine occupies a particular place in the study of historic diamonds for several reasons. First, its double rose cut is exceptionally rare at this scale; most surviving rose-cut diamonds of comparable size were recut into brilliant or cushion forms during the nineteenth-century vogue for maximum brilliance. The Florentine, had it survived intact, would have been one of the finest extant examples of Renaissance and Baroque cutting craft applied to a stone of major size. Second, its pale yellow colour — neither the vivid canary yellow of a Fancy Vivid stone nor the near-colourless of a D-grade diamond — occupies a chromatic territory that was more highly prized in earlier centuries than it is today, when the GIA colour-grading system places such stones in the lower commercial grades unless their saturation reaches Fancy intensity. Third, the circumstances of its disappearance make it a case study in the vulnerability of historic gemstones during political upheaval.

Current Status

The Florentine Diamond has not been seen or verified since the early 1920s. No major auction house, no public collection, and no gemmological laboratory has published a report on a stone credibly identified as the Florentine. The hypothesis that it was recut remains the most widely accepted explanation for its effective disappearance from the market, since a 137-carat yellow diamond of intact double rose form would be immediately recognisable. If recut into several stones or into a single brilliant, it could theoretically exist undetected within the broader population of large yellow diamonds — a population that has grown considerably with twentieth-century production from South Africa, Australia, and other major sources.

The Florentine thus joins the Sancy, the Nassak in its earlier history, and a handful of other major stones as a reminder that even the most celebrated gemstones are not immune to the forces of political catastrophe, commercial expediency, and simple human loss.

Further Reading

• GIA — Famous Diamonds Overview
• GIA — Research on the Florentine Diamond