Diamonds 1 - Flabbergasted by Facets? Perplexed by Proportions?

Here we explain the Basic Round Diamond Cuts

The Four C’s

The four C’s (Cut, Clarity, Colour and Carat) are the basic fundamental characteristics considered when choosing your perfect diamond. When discussing the cut of the diamond we talk about the shape but it is also worthwhile bearing in mind the age and physical dimensions of the diamond. When a gemmologist grades a diamond they will state this 4 C’s but also take additional factors into consideration such as the symmetry, dimensions, proportions and fluorescence (these properties are all stated on the certificates AC Silver provides with diamond solitaires).

Old European Round Cut Diamond

The old European round cut diamond is the predecessor to the modern brilliant cut. The old European round cut (OERC) diamond has a small table (the top facet of the diamond) and is deep. In creating the cut, diamond cutters followed the natural shape of the diamond crystal using up to 80% of the rough product. When graded today, the symmetry of OERC diamonds will often be stated as ‘Fair’, purely because these are hand-cut diamonds and are judged against the symmetry of a laser cut modern brilliant cut diamond.

The old European round cut has a wonderful overall romantic look and is still a very popular choice.

Transitional Modern Brilliant Round Cut Diamond

In 1919, Marcel Tolkowsky analysed the round diamond cut, his calculations look into consideration the amount of light reflected and fire. Every facet within a diamond has the potential to change the direction in which light travels; therefore the positioning of every facet has to be carefully calculated.

This knowledge led to the development of the transitional modern brilliant round cut diamond, where the table of the cut diamond was widened and the depth shorted, allowing more effective light refraction through the stone, giving a higher brilliance than its predecessor.

Contemporary Modern Brilliant Round or Ideal Round Cut Diamond

The contemporary modern brilliant round cut or ideal round cut has been developed by using a mathematical computer model. It is said to be the perfect and most popular diamond cut. The table and depth should both measure roughly 53% - 60% of the total diameter of the diamond (this is something you can ask to see on the diamond grading certificate).

The brilliant style is not solely for the round cut diamond and it often used in marquise, pear, heart, princess and oval cut diamonds. The majority will have a symmetry of ‘Good’ or ’Very Good’ and for the higher quality diamond, a natural blue fluorescence. This fluorescence is a soft-coloured glow that is emitted by the diamond when under an ultraviolet light. This characteristic is not exclusive to the modern brilliant and can also be found in antique diamonds.

I feel I have bamboozled you enough for one day, as a diamond addict I tend to get slightly too enthusiastic. I hope this has given you further insight into the way the round diamond is cut and proportioned.

Please look out for further information on previous and future blogs or feel free contact us at AC Silver where we are happy to answer any questions about our diamonds and their properties.