Brilliants With Sixfold Symmetry

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

Occasionally Brilliants were fashioned with sixfold instead of the normal eightfold symmetry. In this case, the rough stones must have been dodecahedrons and were fashioned using one of the three-face points as the apex. Unlike diamonds derived from dodecahedrons, with four-face points, part of the top of a sixfold diamond could in theory easily be removed by cleaving. This section could then be used to make a Rose.

An Oval Brilliant with both sixfold and fourfold symmetry is in the Grϋnes Gewölbe, Dresden. This Brilliant, weighing over 10ct has no known pedigree. A close study reveals that it was at one time recut from a Pointed Star Cut with sixfold symmetry. It was given a different pavilion with fourfold symmetry, but the culet is still hexagonal. The refashioning was probably done at the end of the seventeenth century since the height proportions, as in most diamonds derived from dodecahedrons, are comparatively modern, with c.32° crown angles and c.43° pavilion angles.