round brilliant diamonds
shape
The round shape is the most famous diamond cut as it accounts for nearly half of all polished diamonds. This is one of the great cuts named for its strong light properties. The ultimate formula for Round Brilliant was developed by Marcel Tolkowsky in 1919: all 58 facets are symmetrically cut, allowing the viewer to see gorgeous lighting effects from any angle, especially on tables. Perfectly symmetrical and perfectly cut diamonds also display Hearts and Arrows. This is a visual phenomenon represented by a pattern of arrows from the center towards the crown in tabletop view, and a heart-shaped pattern formed between the cusp and crown in round-bottom view. “Hearts and Arrows” only occurs in diamonds with the best proportions.
cut
About 60% of engagement rings are set with round brilliant diamonds, so picking the right ring is a handy skill. The most important thing for a round gemstone is its cut. It is best to choose a diamond with a good cut, as lower cut grades may result in poorer light performance due to unbalanced proportions. Proportional defects in a good cut, such as too much or not enough table tops, or uneven facets, can be seen with the naked eye. A well-cut diamond may appear larger and more beautiful due to its brilliance. For example, a well-cut 1.49 ct H SI1 wheel will definitely look bigger and better looking than a well-cut 1.55 ct G VS2.
Some cutters intentionally make the diamond’s girdle thicker to increase the weight of a stone. The girdle is the widest part of a diamond and making it thicker doesn’t make the diamond look bigger. Inspecting the thickness of the girdle is a no-brainer upon choosing a diamond. Otherwise a customer might end up paying extra money for a diamond weight that doesn’t really show itself. However, the girdle shouldn’t be ‘very thin’ also because it makes the edges too fragile and may lead to deformation or damages.
clear
Clarity grades for round brilliant diamonds range from IF (internally flawless) to I3 (inclusive). Inclusions do not affect the overall appearance of a round diamond as much as some other shapes. But it’s still important to try to avoid impurities, especially if they’re located under the table. Inclusions near the edge, in the upper part of the pavilion or crown, do not really affect the diamond’s appearance and ability to sparkle. A good jeweler will be able to hide most of these inclusions under the claws (the metal part that holds the gemstone on a ring or any other piece of jewelry). Gems with inclusions not visible in table view are called “eye cleansers”. It is best to buy exclusively this type of diamond. Not only will they be the best looking of the bunch,
color
Round diamonds are graded in color from D to Z, with D being the whitest and getting yellower to Z. Diamonds within a color group (colorless, near-colorless, etc.) will not differ significantly in appearance, but prices can vary greatly. It is best to choose a diamond that is close to colorless, but not lower than mine, as such a stone will not show as much yellow, but will be much cheaper than colorless. Properly balanced proportions, proper girdle thickness and a “clean” look can compensate for lower colors such as J, so the diamond will still look beautiful by showing a lot of brilliance. However, color grade is still an important factor and needs to be checked carefully.