Oval is one of the most brilliant and sparkly diamond shapes available on the market. Oval cut diamonds make fingers look elongated and appear larger than any other shapes of the same carat weight. If you are interested in buying a diamond with a rounded design and character, our oval cut diamond guide is a must-read.
History of Oval Cut Diamonds
Oval cut diamonds have always been a popular choice among jewellery lovers around the world. They have a long history, undergoing many changes since their early years.
The earliest oval cut diamonds date back to the 1300s; however, they have never been described as “oval” in literature until the 1800s.
One of the most famous oval cut diamonds is the Koh-i-Noor which is believed to be mined in Golconda, India. The first mention of this stone appears in the memoirs of the founder of the Mughal Empire Zahiruddin Muhammad Babur. According to his memoirs, the stone of 739 (!) carats in its original uncut form, was stolen from Rajah of Malwa in 1306.
Being one of the largest diamonds in the world, weighing 105.6 carats, nowadays, the gem is set as one of the jewels within a British monarchy crown and is kept at the Tower of London Jewel House.
The modern oval cut was created by a Russian-born diamond cutter Lazare Kaplan in 1957. Before inventing the modern oval cut, Kaplan was mastering his skills in cleaving, a process in which cracked or heavily included diamonds are cut into smaller, less included stones. He was working with diamonds that other cutters considered “worthless” turning them into gorgeous stones; however, his talent was not fully recognized until he designed the modern oval cut.
Oval Cut Diamond Cut Quality Guide
The quality of the cut is the most crucial factor in maximizing the brilliance and fire of the diamond.
While the GIA (Gemological Institute of America) provides cut grading for some cuts, such as the round brilliant, it doesn’t provide cut grading for oval cut diamonds due to their complex and unique structure.
Oval diamond cut quality recommendations should be regarded as quite subjective and usually general. The table below will serve you as a general guideline for evaluating cut parameters for ideal oval cut diamonds.
| EXCELLENT | VERY GOOD | GOOD | FAIR | POOR | |
|---|---|---|---|---|---|
| TABLE % | 53 - 63 | 51 - 52 or 64 - 66 | 50 or 67 - 68 | 50 or 69 - 70 | <50 or >70 |
| DEPTH % | 57.5 - 62.0 | 55.5 - 57.4 or 62.1 - 65 | 65.1 - 69.0 | 50 - 52.9 or 71.1 - 74 | <50 or >74 |
| GIRDLE | Very Thin to Slightly Thick | Very Thin to Slightly Thick | Very Thin to Thick | Very Thin to Very Thick | Extremely Thin to Extremely Thick |
| CULET | None | Very Small | Small | Medium | > Medium |
| LENGTH TO WIDTH RATIO | 1.30 - 1.50 | 1.25 - 1.29 or 1.51 - 1.55 | 1.20 - 1.24 or 1.56 - 1.65 | 1.20 - 1.24 or 1.61 - 1.65 | > 1.20 or < 1.65 |
Oval Cut Diamond Colour Guide
Colour in oval cut diamonds is graded by the GIA on a scale from D to Z.
As a general rule, smaller oval diamonds hide colour better than larger ones do. That is why, depending on the size of the diamond you are going to purchase, you may not need to buy a premium colourless stone, even if you want it to look white. While it’s usually impossible to see the difference between two colour grades for an untrained eye, the difference in price can be significant.
The chart below will help you to decide on the colour of the oval cut diamond to purchase.
| SIZE | EXCELLENT | VERY GOOD | GOOD | FAIR | POOR |
|---|---|---|---|---|---|
| < .50 ct. | D - G | H - I | J - K | L - M | > M |
| .51-1.0 ct. | D - F | G | H - I | J - K | > K |
| 1.0-2.0 ct. | D - F | D - F | G - H | I - J | > J |
| > 2.0 ct. | D - F | D - F | G | H - I | > I |
Oval Cut Diamond Clarity Guide
Due to their shape, oval diamonds tend to hide blemishes and inclusions well. It is nearly impossible to notice imperfections near the rounded end or where the setting will lay.
While clarity in oval cut diamonds is graded by the GIA on a scale from IF to I3, it is important to understand that everyone has a unique standard for clarity. Some may feel comfortable with inclusions as long as they are not eye seen, while others insist on flawless appearance.
The chart below is a general guide for you to evaluate the clarity in oval diamonds.
| SIZE | EXCELLENT | VERY GOOD | GOOD | FAIR | POOR |
|---|---|---|---|---|---|
| < .50 ct. | FL - VS2 | SI1 - SI2 | I1 | I2 | > I2 |
| .51-1.0 ct. | FL - VS1 | VS2 - SI1 | SI2 | I1 - I2 | > I2 |
| 1.0-2.0 ct. | FL - VVS2 | VS1 - VS2 | SI1 - SI2 | I1 | > I1 |
| > 2.0 ct. | FL - VVS2 | VS1 - VS2 | SI1 | SI2 | > SI2 |
Bowtie Effect in Oval Cut Diamonds
Due to their elongated shape, most oval cut diamonds exhibit bowtie effect, which occurs when some of the light at the centre is leaked and not reflected back to the table.
Sometimes the bowtie effect in oval diamonds is easily noticeable, and other times it is hardly visible. The truth is that a prominent bowtie effect distracts from the beauty of the stone, which is why you should make sure the diamond you choose doesn’t have a dominant bowtie, meaning it’s not the first thing you see when looking at an oval cut diamond.
Oval Cut Diamond Length to Width Ratio
The length to width ratio expresses how relatively long or wide a diamond appears. It is calculated by dividing the length of the diamond by its width.
Each fancy diamond shape has a certain length to width ratio that is considered most appealing for that shape. While personal preference prevails, the optimal ratio for oval cut diamonds is between 1.30-1.50. Diamonds with a lower ratio may look too round, while diamonds with a higher ratio resemble the marquise cut.
Cover image credit: Sotheby’s
