The Round Brilliant Cut Diamond is the most popular diamond shape, representing approximately 75% of all diamonds sold. Due to the mechanics of its shape, the round diamond is superior to fancy diamond shapes at the proper reflection of light, maximizing potential brightness.
Round diamonds cost more on a per carat basis than fancy shapes for two reasons: the demand for round diamonds is very high, and the yield is relatively low. Because more of the rough stone is lost in the cutting of a round diamond, the cost of each carat retained is higher. A typical round diamond (for example; a 1.00 carat, F-color, VS2-clarity, with Excellent cut) may cost 25-35% more than a similar fancy shape.
The round diamond began to rise in popularity in 1919 with the publication of Marcel Tolkowsky’s thesis “Diamond Design: A Study of the Reflection and Refraction of Light in Diamond”. Tolkowsky’s work described the ideal proportions of a round cut diamond for maximizing light return (or brilliance) and dispersion (or fire). The original Tolkowsky specifications (53% table, 59.3% depth, 34.50 crown angle, visible culet) have since been modified as the cut mechanics for round diamonds have perfected over time. These advancements, as well as advancements in technology (such as the use of lasers in diamond cutting), have been adopted by diamond manufacturers to produce the incredibly brilliant cuts we see today in well cut round diamonds.
Evaluating color in round brilliant cut diamonds is subjective. Keep in mind that many customers may actually prefer the ever so slightly warmer colors of a G-H diamond over the cool colorlessness of a D-F diamond. In fact, most of the premium in price associated with round diamonds at the higher end of the color scale is driven by supply and demand; customers want the D-F color grades, and are willing to pay a premium to get them. In a world without diamond color grading, the price premium for higher grades would be much lower, as the actual differences in color are difficult to perceive.
Like color, evaluating clarity in round diamonds is subjective. GIA provides excellent help with their clarity grades. Still, it is important to understand that each customer will have a unique standard for clarity. Some may be perfectly comfortable with an inclusion as long as they cannot easily see it. Others may insist on a more technically flawless appearance.
Many Celebrities have Round Brilliant Cut Diamond Engagement Rings for example Amber Heard, Gisele Bundchen, and Carrie Underwood. After nearly two years of dating, Ashton Kutcher proposed to his former That ’70s Show co-star with a solitaire engagement ring but there’s nothing minimal about that diamond! Estimated to be 5 carats, the ring is likely worth upwards of $260,000.