Diamond cutting, or ‘fashioning’ as it is often referred to, is a modern-day art, based on ancient skills and traditional techniques which have been faithfully handed down and carefully developed for over 600 years.

Those who practice the art are known as Diamond Cutters or ‘Diamantaires’.  Their task is to unlock the brilliance and to reveal the beauty hidden within each rough diamond crystal.

The diamond cutting process involves four separate and distinct stages of planning, preparing, shaping, and polishing.  Every stage has a number of individual steps, each being performed by a dedicated, highly trained expert.

Radiant cut diamonds have become an increasingly pupolar choice for diamond engagement rings in recent years.

The radiant cut was the first rectangular or square cut to have a complete brilliant facet pattern applied to both the crown and pavilion of a diamond.  Following its patented development in 1976 by Henry Grossbard, it became seen as the forerunner of the modern branded diamond.

Until about 10 years ago, the preferred width-to-length proportion was of 1.5 was in keeping with the proportions of an emerald cut, or the rectangular shape it was originally developed for.  Today radiant cut diamonds are more popular in a square shape, with the width to length ratio most commonly 1.2-1.3 or even as low as 1.05 (almost square).

The radiant’s original, patented design had 55 facets: 25 on the crown and 30 on the pavilion - plus or minus a culet.  There are no strict guidelines for table and depth percentages but, as a general rule, look for a table between 59 and 65 percent and a depth between 59 and 66 percent.

The decision to purchase a radiant cut diamond should never just be based on its proportions alone; brilliance and the overall beauty of the diamond also play their part.

Given that radiant cut diamonds are harder to find than brilliant and princess cut diamonds, it is usually easiest to find a loose stone from a place like Larsen Jewellery and to have the ring custom made.

The light performance or “life” of a finished, polished diamond is described as the overall, face-up appearance, produced by a combination of the three optical effects of Brilliance, Fire and Scintillation.  Light performance analysis is used today by leading laboratories as an integral component in the grading of cut quality.

Brilliance

Brilliance is the term used to describe the combined internal and external reflections of unaltered, white light returned from the crown of a diamond.

Fire

Fire is the name used for light which has been dispersed into its individual spectral colours by a prism-effect which occurs when light, after being internally reflected, returns through the angled facets of the bezel.

Scintillation

Scintillation or “sparkle” is the name given to the alternating on-off flashes of Brilliance and Fire created when either the diamond, the light source or the observer is in motion.

Light Pattern

The light returning from within a diamond forms a distinct pattern created by the contrasting light and dark areas of reflected light and light extinction.

A light pattern, in effect, presents a virtual map of the reflective surfaces of the facets and can be used simultaneously to gauge proportions - by comparing the position and degree of light return to that of light leakage - and to determine the degree of internal or optical symmetry of a diamond.

Light patterns are also referred to as symmetry images and are observed and analysed with the aid of special magnifying, reflective imaging or symmetry viewers.

The ideal proportions, precise symmetry and perfect polish of a Super Ideal cut diamond create light reflections which are perfectly balanced, evenly distributed and even of the highest intensity, producing a diamond that not only looks bigger and brighter but, at the same time, displays the highly distinctive, symmetrical pattern known as Hearts & Arrows.

In 1984 a unique optical symmetry viewer known as the Firescope was invented in Japan for the exclusive purpose of visually demonstrating the quality of the cut of a round brilliant cut diamond.

The instrument proved to be so effective that, in 1985, a revolutionary cutting system was developed, based on reflective imaging technology, and diamond cutting took its next evolutionary step with the creation of the Super Ideal cut, which became the world standard of perfection for the round brilliant cut diamond.

Super Ideal cuts soon became popularly known as Hearts & Arrows diamonds and the Hearts & Arrows revolution was born.

Hearts & Arrows are highly symmetrical, reflected light patterns which visually demonstrate the optical symmetry of a Super Ideal cut diamond.  The name refers to the two separate light patterns seen when a Super Ideal cut diamond is viewed, first through the pavilion (face-down) and secondly through the table (face-up) using a special symmetry or Hearts & Arrows viewer.

However, the presence of the Hearts & Arrows pattern does not guarantee that a diamond will be the most brilliant.  In fact, not all Ideal round brilliant cut diamonds even have this pattern.  All major diamond grading laboratories agree that there is no such thing as a set of proportions that is the “best”, so whilst the Hearts & Arrows pattern is an indication of a high quality diamond, it would be a mistake to limit your search to only this type of diamond.