Oval Cut
Oval Cut
The 1957 modified brilliant that rebalanced brilliance and outline
The oval cut is a modified brilliant cut with an oval outline, developed for diamond by Lazare Kaplan in 1957 and now applied across the transparent coloured-stone trade. It typically carries 56 to 58 facets arranged in a faceting plan derived from the round brilliant, with a table, crown, pavilion, and culet or keel line that together return light through the table in a manner comparable to its parent cut. The shape is favoured for its combination of brilliance, finger flattering proportion, and the apparent-size advantage it offers over a round of equal carat weight.
Cut development and structure
Lazare Kaplan introduced the oval brilliant as a refinement of earlier oval shapes that had circulated since the eighteenth century but had never been faceted to deliver true brilliant-cut return of light. The 1957 cut substituted the round brilliant's circular pavilion main pattern with an elongated equivalent that retained the eight pavilion mains and the corresponding crown facet count. The standard arrangement is eight bezel mains, eight star facets, sixteen upper girdle facets, eight pavilion mains, and sixteen lower girdle facets, with a small culet or keel line at the bottom of the pavilion.
Length-to-width ratios in the modern trade run from approximately 1.30 to 1 to 1.70 to 1, with 1.40 to 1.50 to 1 the most commonly preferred. The shape sits well on the finger, makes the wearer's hand appear longer, and gives a noticeably larger face-up appearance than a round of equal weight — typically ten to fifteen percent in standard proportions.
The bow-tie
The principal cut quality consideration unique to the oval is the bow-tie — a darker zone running across the centre of the stone, perpendicular to the long axis, caused by light leakage through the pavilion at the angles where the wearer's head shadows the stone. A small bow-tie is acceptable and is found in most ovals; a pronounced bow-tie is a significant deduction from value. Light bow-ties are managed by tuning the pavilion main angles and the depth-to-spread ratio; the GIA cut report does not assign a comprehensive cut grade for ovals as it does for rounds, but the bow-tie is recognised in the trade as the primary cut grading concern.
Application beyond diamond
The oval brilliant has been adopted across the coloured-stone trade for sapphire, ruby, emerald, tanzanite, tourmaline, aquamarine, and the standard transparent species. The pattern is well suited to coloured stones because the elongated outline displays colour over a larger surface area than a round of comparable weight. For dichroic species, the cutter typically orients the table to optimise hue along the optic axis. Emerald and other species with significant inclusion content sometimes are cut as oval modified brilliants in preference to the more traditional emerald cut, where the masking of inclusions through brilliance is desirable.
In the trade
The oval cut is the second most popular fancy cut for diamond after the princess and is the most popular fancy shape for sapphire and other transparent coloured stones. Oval engagement rings have moved into a leading market position over the last decade, particularly in North America, supported by celebrity-led demand and by the perceived value advantage of the larger face-up appearance.
Quality factors
For diamond, an oval is graded under the standard 4Cs, with the following cut considerations particular to the shape: length-to-width ratio at or near the buyer's preference, minimal bow-tie, symmetry of outline, and proportional crown and pavilion. For coloured stones, the same considerations apply with the addition of colour saturation and zoning. Because the oval cut yields well from typical rough, it is one of the lower-cost transformations from rough to finished stone, which is reflected in the relative pricing of oval-cut material against rounds in the same species.