Diamond Cut Grade, Excellent diamonds, 4 cs buying GemTrove


Diamonds Cut Grade


Out of all of the diamond four C’s, it is the cut which is by far the most critical aspect. The cut of a diamond defines its fire and brilliance, its overall appearance and size, as well as its price. There are many different types of diamond cuts, some that have been around for centuries, and some that have only emerged in recent times. The Gemological Institute of America (GIA) manage cut grading, based on symmetry, depth, and the quality of light reflection.

The properties of the ideal cut

Cuts is graded into five different categories: Excellent, very good, good, fair, and poor. These grades are based on the symmetrical nature of the diamond or gemstone, as well as the angle at which light exits the stone. Generally speaking, a diamond cut grade that falls under the excellent category should be perfectly symmetrical, with the proportions of the cut falling into the ideal ratios for that particular cut style.

For instance, an emerald cut diamond will have a table percentage in between 61 - 69%, with its depth falling between 61 and 67%. It will be perfectly symmetrical, with a thin to a slightly thick girdle, and will not have a culet cut into its shape. Perhaps the most important aspect of a perfectly cut diamond, however, is the way light enters and exits the stone itself, of which the cut plays a huge part.

Light and excellent cuts

Diamonds have been long revered for the brilliance of the light quality that they display. To maximise what is known as the fire and brilliance of the diamond, there are specific proportions that the diamond cut must fall into. Ideally, light entering the diamond should exit the opposite side of the table of which it entered, effectively returning to the eye of the beholder. The brilliant round cut diamond is the perfect illustration of this theory of light reflection at work.

The light’s reflection is controlled by the depth of its pavilion and crown. A diamond cut that will maximise this will often have a shallow pavilion, and be of smaller proportional size. While this may mean that the diamond itself is smaller in carat weight, it will garner a higher price-per-carat due to the increased brilliance. This is one of the reasons why the round brilliant is the most prized of all the diamond cuts, as opposed to other cuts that have bigger carat weights.

Types of diamond cuts shapes

All of the diamond and gemstone cuts can be categorised into three basic shapes:

diamond cutCut: Characterised by precise, triangular facets. Includes the oval, pear, marquise, and round.

cut gradeStep cut: Long, rectangular or square shapes and facets. The emerald and Asscher cuts are prime examples of step shapes.

mixed cutMixed cut: Shapes that combine the theories of both of the above. Examples include the princess and radiant cuts. Many coloured diamonds and gemstones will also fall into this category.

While these cuts have differing prices, it is ultimately up to the personal taste of the buyer. Step cuts offer the least amount of brilliance, but are renowned for their distinctive shape, for example. The popularity of cut shapes is also reliant on personal trends, and there is no better example of this than the step cuts that were favoured during the art deco period of the early 19th century.

Diamond - 0.00 Carat Colour Clarity successfully added to compare

Continue Shopping View Compare