Encyclopedia · Shapes & cuts
Oval cut
By Diamond BrosUpdated 4 min read
What is an oval cut diamond?
The oval is a modified brilliant: the facet pattern of a round brilliant, reshaped to fit an ellipse. Ovals are typically cut in the brilliant style with 57 or 58 facets, and the shape combines the fire and brilliance of a round with an elongated outline.
The brilliant faceting style first emerged around 1700. GIA credits the modern oval brilliant, with 58 facets, to the cutter Lazare Kaplan in 1957.
Why does an oval look bigger than a round of the same weight?
Because carat weight measures mass, not width. An oval has a larger surface area than a round diamond of the same carat weight, which gives the impression of a bigger stone. The elongated shape can also make fingers look longer and more slender.
The effect depends on the individual stone, so compare millimetres, not just carats. The journal piece on why oval diamonds look bigger works through the idea.
What length-to-width ratio is best for an oval?
The ratio is the longer side divided by the shorter side, taken from the measurements on the grading report. An 8.0 x 6.0 mm oval, for example, has a ratio of 1.33. GIA's articles are not identical: one calls 1.30 to 1.50 preferred, another says the most popular ovals fall between 1.40 and 1.50, and a 2013 buying guide gives 1.33 to 1.66 as the span. Read the table as a guide to the look, and let your eye decide. The ranges below are as described by GIA:
| Ratio | How it looks |
|---|---|
| 1.30 to 1.40 | A gently elongated look |
| 1.41 to 1.50 | A longer, more dramatic outline with a slimming effect on the finger |
| Above 1.50 | Rarely cut, because it is impractical |
Is the bow-tie a flaw?
Not exactly. A bow-tie is a dark area across the middle of the stone, shaped like two triangles joined at the centre. It appears where light is blocked, and some degree of bow-tie is always present in an oval because of the shape and its faceting.
What varies is how strong it looks. A well-cut oval keeps it subtle. Look at the stone face-up and tilt it: if the dark band stays wide and heavy, move on to another stone. Ratios above 1.50 are rarely cut at all, so most ovals you see sit in the 1.30 to 1.50 range.
How do you choose a good oval?
GIA names three parts of an oval: the tips at each end, the shoulders (the curved areas between tip and side) and the belly, the widest section. Its advice for judging one comes down to a few checks:
- Symmetry: Excellent or Very Good symmetry matters, so both halves match.
- Outline: smooth, even curves with no flat spots and no bulging shoulders.
- Girdle: a medium thickness is preferred.
- Clarity: VS2 or SI1 offers the best balance of value and appearance, since the brilliant faceting masks small inclusions.
GIA does not give an oval an overall cut grade; the report shows polish and symmetry. As of October 2026, trade press reported (June 2026) that GIA plans to add cut grades for oval, marquise and pear shapes in 2027. AGS Laboratories already extends its cut grading to ovals.
Which settings suit an oval?
An oval suits halo, prong, bezel, three-stone and east-west settings, where the stone lies sideways across the finger.
To compare oval proportions on a real hand, visit a showroom. A custom engagement ring can be built around the ratio you choose, and you can browse engagement rings first.
Key takeaways
- An oval is a brilliant cut, typically with 57 or 58 facets, stretched into an ellipse.
- It has a larger surface area than a round of the same carat weight, so it looks bigger.
- GIA calls about 1.30 to 1.50 the preferred length-to-width ratio: 1.30 to 1.40 gently elongated, 1.41 to 1.50 longer. Above 1.50 is rarely cut.
- Some bow-tie is always present in an oval; the question is how strong it looks.
- GIA grades an oval's polish and symmetry but gives no overall cut grade.
Common questions
Which oval ratio looks most like a classic oval?
As described by GIA, a ratio of 1.30 to 1.40 gives a gently elongated look that flatters most fingers, and 1.41 to 1.50 is longer and slimmer. Pick by eye: hold stones of different ratios side by side and choose the outline you like on the hand.
Do oval diamonds sparkle as much as round ones?
They use the same brilliant style, typically with 57 or 58 facets, and an oval combines the fire and brilliance of a round with an elongated outline. The shape brings a bow-tie, which a well-cut stone keeps subtle, so compare actual stones rather than shapes in the abstract.
What clarity do you need for an oval cut diamond?
VS2 or SI1 gives the best balance of value and appearance. Brilliant faceting masks small inclusions better than a step cut does, but check where the inclusions sit and view the stone in person.
Can an oval go in a bezel or east-west setting?
Yes. Bezel and east-west settings both suit ovals, along with halo, prong and three-stone designs. An east-west oval lies across the finger rather than along it. The setting should be drawn around the actual stone dimensions.
Is the oval a modern shape?
Mostly, yes. Brilliant faceting dates to around 1700 and ovals were not treated as a distinct shape until the late 1800s, but GIA credits the modern oval brilliant to the cutter Lazare Kaplan in 1957, with 58 facets.
Sources
- Oval cut diamond guideGIA · 4cs.gia.edu
- The allure of an oval diamondGIA · 4cs.gia.edu
- Guide to diamond shapes for engagement ringsGIA · 4cs.gia.edu
- Purchasing fancy-shaped diamondsGIA · 4cs.gia.edu
- GIA to launch cut grade for select fancy shapes in 2027Rapaport · rapaport.com
- Light Performance Series: What is light performance?American Gem Society · americangemsociety.org
Related terms
- Bow-tie effectThe bow-tie effect is a dark, bow-tie-shaped shadow across the middle of some elongated diamonds, most often ovals, pears and marquise cuts.
- Round brilliant cutA round brilliant cut is a circular diamond with 57 or 58 facets, arranged to send as much light as possible back to your eye.
- Carat weightCarat weight is how much a gemstone weighs. One metric carat is exactly 200 milligrams (0.2 g), divided into 100 points of 2 mg each.
- Diamond cut gradeA diamond cut grade is a laboratory's rating of how well a polished diamond's proportions and finish handle light.
- Halo settingA halo setting surrounds a centre stone with a ring of smaller accent stones.
- Polish and symmetryPolish and symmetry are the finish grades on a diamond report.
- Cushion cutA cushion cut is a diamond with a square or rectangular outline, curved sides and rounded corners, like a pillow.
In the shop
Talk it through with a jeweller
Bring your questions to a private appointment at any of our 3 showrooms, in Mississauga or Brampton, or meet by video. Nothing is ordered until the design, the stone and the price are confirmed with you.