The Unique Spherical Diamond
On a recent field trip to the gem cutting centre of Idar-Oberstein in Germany, a group of gemmologists from the Gemmological Association of Great Britain, Gem-A, were privileged to be shown a most unusual diamond. The stone, cut by master diamond cutters Ph.Hahn & Sohne, had all the appearance at first sight of being a pearl. It was only on closer inspection that its reflective properties revealed it to be something far more exciting.
“We just had the idea to try such a round ball,” said Dieter Hahn, the CEO of Ph.Hahn & Sohne, the oldest diamond cutting workshop in Germany.
The diamond material was not of gem quality but a large rock of industrial rough. The result was a perfect sphere, opaque and with a highly reflective surface with a diameter of 10mm and a weight of 9.41cts.
The expertise of this diamond cutting company had produced a stone of unusual beauty and unique ability. Its resistance to friction, diamond being the hardest material known to man, enabled it to roll at speed, without loss of velocity, across a flat surface.
The town of Idar-Oberstein has long been famed for its gem cutting expertise with a history that dates back 400 years. Originally Idar and Oberstein were separate valley towns united by a river but the geological finds within their hills of quartz, including amethyst, jasper and agate meant that mining became integral to the area. Cutting workshops grew up along the river which powered the mills that turned the huge sandstone wheels and cut the stones. This heritage of expertise in gem cutting has resulted in an area famed for its advanced lapidary skills and its excellence in innovative techniques.
It is these skills that have been used to such incredible effects in the cutting of this sphere shaped diamond. So it may be worth taking a closer look if you see a pearl with remarkable reflection. It just might be more than you think.
This article was written by our friend Carole Spooner (FGA) (DGA) who travelled to Idar Oberstein and was kind enough to share her story.