Ruby rose dating history

A diamond's cut is evaluated by trained graders, with higher grades given to stones whose symmetry and proportions most closely match the particular "ideal" used as a benchmark.The strictest standards are applied to the round brilliant; although its facet count is invariable, its proportions are not. Diagram of old diamond cuts showing their evolution from the most primitive (point cut) to the most advanced pre-Tolkowsky cut (old European).

Known as Mazarins, they had 17 facets on the crown (upper half).The practical history of diamond cuts can be traced back to the Middle Ages, while their theoretical basis was not developed until the turn of the 20th century.Design creation and innovation continue to the present day: new technology—notably laser cutting and computer-aided design—has enabled the development of cuts whose complexity, optical performance, and waste reduction were hitherto unthinkable.In 1919, Marcel Tolkowsky analyzed this cut: his calculations took both brilliance (the amount of white light reflected) and fire into consideration, creating a delicate balance between the two.

Tolkowsky's calculations would serve as the basis for all future brilliant cut modifications and standards.

Different countries base their cut grading on different ideals: one may speak of the American Standard or the Scandinavian Standard (Scan. The rose cut is omitted, but it could be considered intermediate between the old single and Mazarin cuts.