Program Speaker: Scott Sucher, Replica Diamonds.
by Nancy L. Attaway

The New Mexico Faceters Guild was very pleased to have facetor Scott Sucher show his remarkable replica collection of sixteen of the noted famous diamonds in history. Scott captured the full attention of Guild members as he related his experience cutting these selected replicas in cubic zirconia, a cutting project that spanned the years between 1980 and 1988. The replicas in his display included the Tiffany, the Dresden Green, the Hope, the Florentine, the Sancy, the Dudley, the Pascha, and nine Cullinan diamonds.

Scott had seen collections of replicas rendered in quartz, including the one owned by the Lazadro Mineral Museum of Lapidary Arts in Chicago. However, Scott believed that the optical properties of cubic zirconia would better mimic those of diamond. The refractive index for diamond is 2.417. The refractive index for quartz is 1.544 to 1.553, much lower than that of diamond. The refractive index for cubic zirconia is 2.17, very close to the refractive index of diamond.

Scott chose to cut only sixteen replicas of the famous diamonds of history. He wanted to eliminate the repetition of shapes found in the total collection. He said that many of these diamonds are clear, having no color. Only several exhibit any color tones. He decided to cut replicas of the ones that showed color and interesting faceting patterns.

Scott, who enjoys historical references on old diamonds, delved into a bit of history regarding some of these famous diamonds. He spoke of the noted diamond merchant, John-Baptiste Tavernier, who traveled extensively throughout Europe and the Middle East during the seventeenth century. Tavernier described a number of great Indian diamonds in his journals. The 112-carat French Blue that Tavernier procured from India and sold to Louis XIV later became the 45.52-carat Hope Diamond. Tavernier also described the huge table facet of the Great Table diamond, which has since disappeared. Scott mentioned the 3106-carat rough Cullinan and how it was water clear and considered to be the finest quality of all the famous diamonds. Scott said that the 41-carat pearshape Dresden green diamond is the only large naturally colored green diamond. Scott recommended reading the history regarding the various famous diamonds to discover who they belonged to, how their ownership changed with time, and their particular place or significance in history.
Scott shopped for enormous chunks of cubic zirconia, and sometimes he had to wait months and even years for the rough. He only purchased cubic zirconia made in America. Scott allowed enough rough in each large chunk of cubic zirconia to cut two of the same replicas, just in case he made a faceting error and had to start over again.

Scott researched diagrams and studied the pictures and dimensions of the famous diamonds in history from reference books in libraries. He found an original copy of the manuscript from Tavernier and checked his drawings and the height to width to depth ratio. Scott traced every drawing he found, noting the eight-fold symmetry. He calculated the volume to shape density by hand. (Remember, this was during the days before we had GemCad.) Scott noted that the Spoon Maker’s Diamond in the crown jewels of Turkey was a pearshape stone with parallel rows of equilateral triangles. His research of the existing diagrams for some of the replicas revealed many errors in design. Scott cautioned cutters about using the designs by Tom Barbour that were published in Lapidary Journal in the early 1960’s.

Many references mentioned metric carats, an old unit of measurement. According to George E. Harlow’s book, The Nature of Diamonds, modern carats are metric, five carats to the gram as defined in 1907, designated with decimal notation. Prior to 1914, there existed many carat standards that usually were measured with fractions of carats, and these could not be converted to metric carats without knowing the standard. (See Ian Balfour’s book, Famous Diamonds, for more information on this problem.) A carat is now a unit of weight equal to 200 milligrams.

Scott located other cutting data from conversations with several gem and mineral curators. Scott obtained much of his needed information on the Hope Diamond from the curator of the Smithsonian Museum, who expressed great interest in Scott’s faceting project.

Scott held Guild members spell-bound as he explained how he calculated the required measurements for his various selected replicas. Often, not all the angle are available and Scott had to make some guesses about the cutting angles. To check his designs, Scott calculated the volume of the stone using the density of CZ and compared that to the volume of the original design. In most cases he was able to hit his mark within one or two percent error. In some cases, he had to recompute his design many times before he started cutting.

Scott explained how to best cut large chunks of cubic zirconia that weigh over one thousand carats. He used a fine saw blade to minimize damage. He used large globes of dopping wax to hold the stones on the dop. He recommended grinding on coarse grits like the 80/100 or a 260 and then move to a lap with 3,000 loose grit on aluminum, using crystal lube as a carrier. He always used eight inch laps. Scott polished with a Last Lap, a ceramic lap, an ultra lap, a chrome lap, a cerium lap, and an alumina oxide lap. His best polishing results were obtained with 100,000-grit diamond on a tin/lead lap, using also the occasional bit of 50,000-grit loose diamond. Scott said that polishing each facet required a lot of pressure, and he would have to bear the stone down very hard on the polishing laps, especially for the larger facets. He cautioned about using too much crystal lube, however, as he used very little. Scott facets with a forty year old Ultra Tech faceting machine.

Scott logged 90 hours faceting the Cullinan 1 Diamond and 150 hours cutting the Cullinan 2 Diamond. These two stones were cut from a 3900-carat chunk of cubic zirconia. Scott said that while sawing that chunk of cubic zirconia, it inadvertently split into three pieces instead of two. He barely had enough rough required for the two stones. Scott spent 60 hours cutting the Florentine Diamond, a double-Dutch rose, and it became his personal favorite.

Scott graciously extended an invitation to Guild members who plan to cut any replicas of the famous diamonds in history to call him, as he would provide what information he could. The Guild has waited years to hear Scott Sucher speak about cutting these replicas. Scott served in the United States Air Force as a fighter pilot and traveled to many parts of the globe, and it was difficult to schedule him for a presentation during that time. It was truly worth the wait to listen to him explain his methods, problems, and solutions. Scott Sucher’s talk was absolutely fascinating.