Up to this point in the development of diamond cutting, stones were cut for symmetry of outline alone and no attempt was made to utilize the remarkable optical properties of the diamond, which enable it, when properly proportioned in the cutting, to reflect back to the eye most of the light which falls upon it. Toward the close of the seventeenth century Vincenzio Peruzzi, a Venetian, began to cut diamonds on this principle. With this discovery, no longer the lapidary labored solely to produce a maximum weight and symmetry of outline, but he endeavored to combine with these the very essential factor of the brilliancy of the stone. And with increased skill in the art, more facets were added to beautify the form and enhance the radiance of the gem. Sixteen additional “corner facets” above and sixteen below the girdle rendered it rounder and more symmetrical, and subsequently eight extra facets grouped about the table completed the fifty-eight of the modern brilliant.
It is a singular and somewhat significant fact that the historical evolution of the modern brilliant as here traced is precisely its actual evolution under the hands of the diamond cutter. The facets are added to the stone in just the order in which they were developed through the centuries.