A GUIDE TO ROUND CUT DIAMONDS
ROUND CUT DIAMONDS: The Basics
Modern round brilliant cut diamonds are composed of flat polished surfaces called facets. These facets are arranged in a specific pattern to receive light and to return light to a viewer’s eye. Round brilliants are usually composed of 57 facets that are divided into 3 main parts: Crown, Girdle, and Pavilion.
Round cut diamonds are extremely popular, representing over 75% of all diamonds sold. In 1919, Marcel Tolkowsky outlined the specifications for the ideal cut diamond – his findings translated into a diamond with an abundance of fire and brilliance, and the modern round brilliant cut is modelled on his formula. The round brilliant is considered a timeless and versatile style, suiting a diverse range of tastes and working perfectly for various items of jewelry.
ROUND CUT DIAMONDS: Anatomy
CROWN – The crown is the top part of the diamond that sits above the girdle. Light enters a diamond through the crown facets. The crown is composed of bezel facets (crown mains), star facets, upper girdle facets (upper halves), and a table facet.
Table – Octagonal in shape, the table is the largest diamond facet. It sits at the top of the crown.
Bezel Facet – Also known as the “crown mains,” the bezel facets are kite shaped and sit between the table and the girdle edge. There are 8 bezel facets on a round brilliant.
Star Facet – These triangular facets extend from the table to the upper girdle facets. There are 8 star facets.
Upper Girdle Facets – Also known as the “upper halves,” these triangular facets are closest to the girdle edge. There are 16 upper girdle facets.
The girdle separates a diamond’s crown and pavilion. Diamond girdles are often polished with tiny facets. Diamonds can also be found with girdles that have a frosted or slightly waxy appearance, finished but not faceted.
The pavilion is the bottom half of the diamond that sits below the girdle. The pavilion facets reflect incoming light that has entered through the crown facets. The pavilion is composed of lower girdle facets (lower halves), pavilion main facets, and an optional culet facet.
Lower Girdle Facets – Also known as “lower halves,” these triangular facets extend from the bottom of the girdle to the culet. There are 16 lower girdle facets.
Pavilion Main Facets – Kite or diamond shaped facets that often take on the appearance of arrows. There are 8 pavilion mains.
Culet – A small facet at the very bottom of a diamond. Most modern round brilliants do not have a culet. The bottom usually comes to a sharp point where the pavilion mains meet.
THE ROUND BRILLIANT CUT
Before the emergence of the round brilliant cut, the Old European cut was a popular choice for diamond jewelry. Though it bears a strong resemblance to the modern round brilliant, the old European cut featured chunkier, triangular facets, a small table, and a prominent culet.
The beauty of a brilliant cut is in the symmetrical alignment of its facets and it’s ability to reflect and refract light. In order for this form of cut to be successful, a high-quality cut and polish is necessary to ensure the maximum light return. Although a round brilliant patterning is specifically designed for brilliance, the quality of the cut and the remaining quality factors (The Four C’s) will all impact on how well the diamond performs. A round brilliant cut is adept at concealing inclusions and color, so a careful look at the stone to check if it is eye clean and without yellow/brown hues will be necessary.
THE ROUND BRILLIANT CUT GRADE
When choosing a significant diamond of any shape, certification is key. The certifying lab will award the diamond grades for cut, colour and clarity. The goal for most buyers is to go above and beyond the lab grading for cut as the quality brackets can be fairly broad. The process of finding a good cut begins with assessing the proportions and eliminating any duds; Pricescope’s HCA tool can help narrow down your search. Beyond this, tangible data such as Hearts and Arrows view and ASET reports will come into play. The most reputable vendors will provide advance performance images for their diamonds, allowing you to fully appreciate the quality of the cut.
THE ROUND BRILLIANT COLOR GRADE
The facet arrangement of a round brilliant allows it to reflect an abundance of light; as a result, this sparkle will help to mask color tints that the diamond has. Color is one of the most personally subjective quality factors, so there is no correct answer as to what color grade is most beautiful for a round cut diamond, although colorless diamonds are the most expensive. Many buyers take advantage of the perceived color concealment of the round brilliant by opting for ‘near colorless’ or lower in order to balance budget and beauty.
THE ROUND BRILLIANT CLARITY GRADE
When it comes to clarity, an eye-clean diamond is a goal for most buyers. While there is an undeniable allure surrounding flawless and microscopically clean diamonds, they are much more rare and expensive. When it comes to loose stones, buy from online vendors who provide full lab certification with clarity stone plots, and high-res images and 360 videos so that you have a complete view of the diamond in question. If shopping in a store, be sure to take a look at the diamond in various lights and learn the correct way to use a jewelers’ loupe.
THE ROUND BRILLIANT PRICES
A round brilliant diamond is a bit more expensive than other shapes on the market. The first cause of this is demand – demand drives the price and round cut diamonds have been the most popular shape for over a hundred years because of its propensity for great fire and brilliance. The second cause is yield in the cutting process.
To create a round brilliant diamond, a large percentage of the rough is polished away. This also demonstrates one of the reasons a better cut grade commands a higher price. In many instances, cutters will aim for maximum carat yield, sacrificing cut quality in the process.
You can use our Pricescope price calculator to trial various quality combinations and assess the current market prices for round brilliant diamonds.
THE ROUND BRILLIANT DIAMOND: Conclusion
The round brilliant is the most popular and most studied diamond shape on the market. This benefits the consumer, who will be able to accurately research this highly coveted shape and find a great diamond for a great price. Our valued contributors, diamonds experts and extensive resources are on hand to assist your search.