Cushion-Shaped Brilliants

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

A cushion-shaped diamond is either square or rectangular, with clearly rounded corners and usually slightly rounded sides. The name, of fairly recent origin, is not ideal since real cushions are often completely round or obsolutely square, but it is far better than the terms Old Mine Cut or Old Miner which were introduced at the end of the last century to describe the kind of cut applied to most Brazilian rough. The fashion for round Brilliants, incidentally, coincided with the discovery of the South African mines.

Many of the Baroque cuts had cushion-shaped outlines, but the shape was less important than the fashioning. Cushion shapes were introduced more and more when the old Table Cuts were refashioned. Many Table Cuts had blunt or missing corners which had to be disposed of without reducing the size of the gem. The easiest way to do this was to round the corners off. The second half of the eighteenth century was a great period for recutting unfashionable designs, and the cutters aimed to achieve a slightly larger display from octahedral rough than would have been possible if the gems had been given sharp corners. From this point on, jewelers used a regular mixture—which appears to have been entirely acceptable—of square and cushion-shaped Brilliants, combined with occasional diamonds of round, pear-shaped or other outlines. Normally the gems were placed according to their shapes in order to accentuate the design of the piece of jewelry, but sometimes—as, for instance, in opulent necklaces made soley of large diamonds—the stones were arranged in order of size irrespective of shape. As long as bruting remained a long and arduous process, nearly all dodecahedrons were fashioned into cushion shapes. We have evidence of this in the writings of several authos: Dutens (1773), for instance, says that ‘de nos jours on prefère la forme dodecaèdre, comme las plus propre à acquerir par le taillage la belle proportion voulue..’

Today, the circular Brilliant Cut is the standard, and other outlines are only applied when the rough particularly favors them. But during the last hundred years a number of large Cushion-shaped Brilliants have been fashioned, including the Tiffany, the Rojtman, the Jubilee, the Assher and the Red Cross.

The Deepdeene Diamond (104.52 ct) was widely discussed in the 1970s when questions were raised about is unusual golden-yellow color. With the Tiffany diamond, there has been exaggerated retention of weight simply in order to have a diamond of over 100 ct, a goal which could not have been achieved if correct proportions had been applied. The drawings show that the diamond had a very large table (c. 64 percent) and very wide crown angles (over 50°), resulting in a high crown. The girdle is too thick (6 percent) for a gem of this size. The pavilion, however, is well proportioned; it follows the rule of 45° angles and has a reflecting culet of about 7 percent. The broad pavilion facets indicate that it was cut in the second half of the nineteenth century.