Round Diamond Engagement Ring: The Complete Guide

The round diamond, in a brilliant cut, is the most popular shape for an engagement ring, and for good reason: it returns the most light. Timeless, it suits every hand and every setting. In this guide: what makes a beautiful round diamond (cut, proportions, color, clarity), what size to expect for each carat weight, which setting and wedding band to choose, and how much a round diamond ring costs. All our rings feature lab-grown diamonds certified by IGI or GIA, in 18k gold or platinum, to try on in our 10 showrooms in France.

Contents
Why this diamond · Size and carat: the chart · What to check · Comparing shapes · Which setting · Which metal · Which wedding band · Price · Frequently asked questions

Why choose a round diamond?

• It is the most brilliant. Its 57 or 58 facets are calculated to return as much light as possible to the eye: no other shape sparkles as much.
• It is timeless. The round solitaire never goes out of style: it is the ring you will still be wearing fifty years from now.
• It is the easiest to compare. It is the only shape that receives an official cut grade on IGI and GIA certificates: you know exactly what you are buying.
• It is forgiving on color. Its brilliance hides a slight tint very well: an H color looks white to the eye.
• It goes with everything. Solitaire, pavé, halo, three-stone, straight wedding band: every setting suits it.

Round diamond: size, carat and price

Carat measures weight, not size. The chart below gives the usual dimensions of a well-cut round diamond, along with the price of our Montaigne round solitaire in 18k gold, for each of our three diamond qualities.

Note: going from 1 to 2 carats doubles the weight, but the diameter grows by only about 27%, because the stone also gains depth. At around 0.50 carat, the round remains delicate and elegant; at 1 carat, it is the classic solitaire; above 1.50 carats, it becomes spectacular.

Choosing your round diamond: 5 things to check

1. Cut quality

For a round, this is the most important criterion, even before carat weight: an Excellent cut (or “Ideal” at IGI) makes all the difference in brilliance. A poorly cut diamond, too deep or too shallow, leaks light and looks dull, even if it is very clean. Aim for Excellent in cut, polish and symmetry.

2. Proportions

Two benchmarks on the certificate: a table of about 54 to 58% and a total depth of about 59 to 62.5%. Within this range, the stone returns as much light as possible and shows a diameter true to its weight. To read a certificate in detail, see our article on lab-grown diamond certification.

3. Color

The round is the shape that hides color best. An H color looks white to the eye, even in white gold. For an icy white in platinum, choose F or D. We offer three qualities: H/VS2, F/VS1 and D/VVS1.

4. Clarity

The many facets of the brilliant cut disperse light and hide small inclusions well: a VS2 clarity is eye-clean. Beyond that, it is a matter of principle rather than anything visible.

5. Fluorescence

Some diamonds glow blue under ultraviolet light. When none or faint, it has no effect; when strong, it can give some stones a milky appearance. It is shown on the certificate, and our advisors check it with you.

Round or oval: which to choose?

The round is the most brilliant and most timeless shape. The oval offers almost the same brilliance, with an elongated silhouette that looks about 10% larger at the same weight. At Laveran, for the same carat weight and quality, a round solitaire costs the same as an oval solitaire: the choice comes down to taste alone. Here is how the round compares with other shapes:

To go further, read our guide which diamond shape to choose for an engagement ring, or which ring to choose for your hand shape.

Which setting for a round diamond?

• The solitaire, the engagement ring par excellence. Four prongs show more of the diamond; six hold it even more securely: this is the Montaigne round, from €880.
• The pavé band adds small diamonds along the shank: this is the Vendôme round, from €1,280.
• The halo surrounds the stone with a circle of diamonds and makes it look noticeably larger: this is the Odéon round, from €1,480, or the Odéon double halo, from €1,580.
• More distinctive designs: the Madeleine, the Étoile or the Louvre.

Yellow, white or rose gold, or platinum?

All our rings are available in 18k yellow, white or rose gold, and in 950 platinum. The round works with every metal: white gold and platinum for a classic, luminous solitaire; yellow gold for a warmer, more vintage look; rose gold for a soft touch. Platinum is the densest and most durable of the four. To compare them all, see the differences between yellow, rose and white gold.

Which wedding band goes with a round diamond ring?

The round solitaire is the easiest ring to pair: almost any straight wedding band sits against it. For a matching set, the Montaigne Round Diamond Wedding Band echoes the same stone all the way around the finger; a half-eternity band leaves the spotlight on the solitaire. To know which order to wear them in, see in which order to wear your engagement ring and wedding band.

What about color?

The round also comes in colored diamonds: our Vendôme and Odéon rings are available with a blue, pink or yellow round diamond, an alternative to sapphire with the hardness of diamond. To learn more, read our article on colored lab-grown diamonds.

How much does a round diamond ring cost?

At Laveran, a round solitaire starts at €880 and the 1-carat solitaire is available from €1,744, with an IGI or GIA certificate. The price depends on four things: carat weight, diamond quality (H/VS2, F/VS1 or D/VVS1), setting and metal. The chart above gives the details carat by carat.

A lab-grown diamond costs considerably less than a mined diamond of the same size and quality, which often means you can choose a more generous carat weight for the same budget. To go further: how much a lab-grown diamond costs, the 1-carat lab-grown diamond and the average price of an engagement ring. Our diamond guide also explains each of the 4Cs in detail.

How does buying from Laveran work?

1. You book an appointment in one of our 10 showrooms in France or by video call. The appointment is free, with no obligation.
2. You compare stones and settings. An advisor shows you several round diamonds, you try them on, and your ring size is taken with a professional ring sizer.
3. We craft your ring in your size, in 18k gold or platinum, with the diamond you chose.
4. You receive your ring with the stone’s IGI or GIA certificate, whose number is laser-inscribed on the diamond.

Frequently asked questions

What size is a 1-carat round diamond?

About 6.4 mm in diameter for a well-cut diamond. Exact measurements are listed on each stone’s certificate.

What is the difference between a round diamond and a brilliant diamond?

A round diamond is almost always brilliant cut (57 or 58 facets): hence the term “round brilliant.” The brilliant cut is also used on other shapes, such as the oval, pear or cushion.

What is the most important criterion for a round diamond?

Cut quality. A round with an Excellent cut sparkles noticeably more than a poorly proportioned one, even a heavier or cleaner one.

Four or six prongs?

Four prongs reveal more of the stone and make it look slightly more square; six prongs hold it more securely and emphasize its roundness. Both are suitable for everyday wear.

How much does a 1-carat round diamond solitaire cost?

At Laveran, €1,744 in H/VS2 quality, €2,096 in F/VS1 and €2,360 in D/VVS1, in 18k gold, with an IGI or GIA certificate.

Round or oval: which looks bigger?

At the same weight, the oval looks about 10% larger thanks to its elongated shape. The round, for its part, sparkles more.

Is a lab-grown diamond a real diamond?

Yes. It is pure carbon, with a hardness of 10 and the same optical properties as a mined diamond; only its origin differs. Each stone is certified by IGI or GIA, with its number laser-inscribed.

Can I see the rings before buying?

Yes, in one of our 10 showrooms in France, by appointment only and with no obligation, or by video call. Each ring is then crafted in your size.

Other diamond shapes: oval · cushion · princess · pear · marquise · emerald cut

See also: all our engagement rings · our diamond wedding bands · how to measure your ring size · caring for lab-grown diamond jewelry