European history of diamond cutting

Prior to the late Middle Ages, diamonds were utilized in their octahedral state and anhedral (poorly formed) diamonds were simply not used in jewelry. This marks the beginning of the history of diamond cuts in Europe. The early "improvements" on nature's design comprised simply polishing the faces of octahedral crystals to produce flawless facets or shaping the desired octahedral shape out of an unattractive piece of rough. The point cut, which was first used in the middle of the 14th century, was invented in Nürnberg in 1375. The table cut, which was created by polishing or grinding off the top of the octahedron, was an improvement on the point cut by the middle of the 15th century.

It was also realized how important a culet was, and some table-cut stones may include one. The previous single cut was formed by adding four corner facets (or old eight cut). Neither of these early cuts would exhibit the qualities that make diamond so valuable today, such as its strong dispersion or fire. A table-cut diamond would seem black to the eye, as they do in paintings from the time, and was esteemed at the time for its exceptional hardness and adamantine shine. Because of this, colorful gemstones like sapphire and ruby were far more common in that era's jewelry.

Using a tool he created, the scaif, Lodewyk (Louis) van Berquem, a Flemish polisher from Bruges, invented the method of absolute symmetry in the arrangement of facets circa 1476. He fashioned gemstones in the pendeloque or briolette shape, which had pear-shaped facets on both sides. The rose or rosette, which was essentially a crown without a pavilion, was first made in Antwerp in the middle of the 16th century. It likewise included triangular facets arranged in a symmetrical radiating pattern, but the bottom of the stone was left flat.

There is also speculation that Western cutters were influenced by Indian stones because several huge, well-known Indian diamonds from the past (such as the Orloff and Sancy) also have a rose-like cut. Some of these diamonds may even precede the Western adoption of the rose cut. However, due to the revered position of diamonds in India, Indian "rose cuts" were much less symmetrical since their cutters were more concerned with conserving carat weight. In either case, the depth, quantity, and arrangement of facets of the rose cut continued to change.

The middle of the 17th century saw the introduction of the first spectacular cuts. They were called Mazarins, and their crown featured 17 facets (upper half). They are sometimes known as double-cut brilliants since they are thought of as an improvement over older single cuts. Later, a Venetian polisher named Vincent Peruzzi expanded the crown's facets from 17 to 33 (creating triple-cut or Peruzzi brilliants), greatly enhancing the cut gem's fire and brilliance, which were already unmatched by those of the rose in the Mazarin. However, when viewed today, Peruzzi-cut diamonds appear incredibly boring in comparison to modern-cut diamonds.

These early brilliants were all cross-sectionally rounded squares or rectangles (rather than circular). By the early 18th century, these were widespread and known by the general name of cushion—what are now referred to as old mine cuts. Later, the old European cut, which featured a shallower pavilion, a more rounded form, and a different facet arrangement, was created. The most advanced cut in use throughout the 19th century was the old European.

Modern diamond cutting and diamond cuts, foremost among them the round brilliant cut, were made possible by the advent of diamond saws and high-quality jewelry lathes around 1900. Marcel Tolkowsky examined this cut in 1919; his calculations created a careful balance between brightness (the quantity of white light reflected) and fire. All future revisions and standards for brilliant cuts would be based on Tolkowsky's estimations. The "ideal" cut model by Tolkowsky is imperfect. The initial model was intended to be a generic reference and omitted or underaccounted for a number of characteristics of diamond cut.

Bruce Harding created a new mathematical paradigm for gem design in the 1970s. Since then, a number of organizations have created diamond cuts using computer models and specialized scopes.