Round Brilliant Cut Diamonds

While all modern round diamonds are technically brilliant cuts, the term “round brilliant” specifically refers to the standardized 57-58 facet pattern perfected in the 20th century. Earlier round cuts like Old European or transitional cuts feature different facet arrangements and proportions that produce distinctive vintage appeal but less optimal light performance. Modern round brilliants follow precise mathematical proportions designed to maximize light return, creating superior sparkle in these natural gems. When purchasing, note that “round brilliant” indicates adherence to contemporary cutting standards, while “round cut” might encompass both modern and antique variations, affecting both aesthetic character and price.

Cut quality dramatically impacts round brilliant diamond pricing, with excellent cut grades commanding 10-20% premiums over very good cuts of identical carat weight, color, and clarity. This price difference reflects both increased production costs (more rough diamond is sacrificed to achieve ideal proportions) and superior light performance. Poorly cut round brilliants can appear smaller, darker, and significantly less brilliant despite having identical specifications on paper. For value-conscious collectors seeking conflict-free stones, prioritizing excellent cut quality often provides more visible beauty than spending equivalent amounts on higher color or clarity in a lesser-cut stone, making it a worthwhile investment.

“Hearts and arrows” refers to a distinctive pattern visible in perfectly cut round brilliant diamonds when viewed through specialized optical tools. Under proper magnification, these premium stones display eight symmetrical arrows when viewed from the top and eight perfect hearts when viewed from the bottom. This optical phenomenon occurs only in diamonds with exceptional precision in facet alignment and symmetry, representing the pinnacle of cutting craftsmanship. Though these high-quality gems typically cost 10-15% more than excellent-cut diamonds without the pattern, many collectors value this rare feature as tangible proof of extraordinary cutting precision and superior light performance worth the additional cost.

Table size significantly influences a round brilliant diamond’s visual character, with ideal proportions falling between 54-58% of the diamond’s diameter. Larger tables (59-64%) increase brightness but reduce fire (colored light dispersion), creating a whiter appearance with fewer rainbow flashes. Smaller tables (52-54%) maximize fire at the expense of some brightness, producing more colorful light play. Neither approach is inherently superior—the preference remains aesthetic rather than quality-based. When selecting these precious stones, consider which light performance characteristic you value more; brightness-focused collectors typically prefer slightly larger tables, while those prioritizing dramatic fire might select stones with smaller tables, affecting both appearance and purchase cost.