Diamond shapes and cuts: oval, brilliant, and princess

Choosing the shape of a diamond means defining the character of an engagement ring for decades to come. The round brilliant accounts for 75% of diamonds sold worldwide, yet each of the nine other popular shapes offers its own distinct visual identity. Here is the complete guide to the ten most sought-after diamond shapes: their technical characteristics, their brilliance, their effect on the hand, and how to choose between them based on your personal style.

The round brilliant is the undisputed benchmark of diamond cutting. 57 or 58 facets arranged according to a geometry optimised for light reflection. It is the shape that delivers maximum brilliance: every facet is calculated to return as much light as possible to the eye. Demand is such that the round brilliant typically commands a premium of 20 to 30% more than fancy shapes of equivalent quality, simply because the cutting process results in greater loss of rough material. The round brilliant suits every mounting style: classic solitaire, pave halo, trilogy, vintage. It is the timeless shape par excellence.

The oval is an elongated brilliant. It retains a brilliance close to that of the round (similar facets, comparable arrangement), yet its elongated format creates a slimming visual effect on the hand. At equal carat weight, an oval often appears larger than a round, simply because its table surface is more extensive. The modern oval dates from the 1960s, popularised by cutter Lazare Kaplan. Be mindful of the bow-tie effect: a dark, bow-tie-shaped shadow at the centre of the diamond, visible on certain poorly proportioned ovals. A well-cut oval features a length-to-width ratio between 1.35 and 1.50.

The princess is the most brilliant square shape. A modern cut invented in the 1980s, it combines V-shaped facets arranged from the corners toward the centre, generating intense scintillation comparable to that of the round brilliant. The princess requires a mounting that protects its four pointed corners, which are naturally vulnerable. Worth noting: the princess loses less rough material during cutting than the round brilliant. This is one of the reasons it costs 20 to 30% less per carat.

The cushion evokes a rounded pillow with softened corners. It is an historic shape, popularised in the nineteenth century, that has experienced a remarkable resurgence over the past fifteen years. The cushion exists in two variations: classic cushion (broad facets, a soft, lustrous glow) and modified brilliant cushion (additional facets, more intense scintillation). The cushion cut lends itself particularly well to vintage settings and pave halos. Its soft, almost organic appearance contrasts beautifully with the precise lines of the round brilliant.

The Emerald (or emerald cut) is a rectangular shape with parallel step facets. Unlike brilliant cuts, which prioritise scintillation, the emerald cut relies on clarity and a mirror effect. The broad, flat facets act like windows: any inclusions become immediately visible. An emerald cut diamond demands high clarity (VS2 minimum recommended). The emerald cut exudes an Art Deco elegance. Simple settings, often flanked by two lateral baguette cut stones, highlight its geometric lines.

The pear combines a rounded end with a pointed tip. A hybrid between the round brilliant and the marquise, the pear visually elongates the fingers and offers brilliance comparable to a round. Traditionally worn with the point toward the nail, it suits both engagement rings and pendants. Symmetry is critical: a poorly cut pear will show uneven shoulders or a pronounced bow-tie effect. The ideal length-to-width ratio falls between 1.45 and 1.75.

The marquise is a boat-shaped cut, elongated to two pointed ends. It maximises the apparent carat weight: at equal weight, a marquise appears larger than any other shape. The elongating effect on the hand is spectacular. Historically, the marquise is said to have been created for Louis XV, inspired by the lips of Madame de Pompadour. Today, it evokes a dramatic, vintage or bohemian style. Like the pear, the marquise requires a setting that protects its points.

The Asscher is a square emerald cut, created in 1902 by Joseph Asscher in Amsterdam. A step-faceted shape with cropped corners, the Asscher presents a unique optical effect: a "hall of mirrors", a play of deep reflections that mesmerises under the light. The Asscher demands the same high clarity as the emerald cut. It is a rare shape, prized by connoisseurs and Art Deco enthusiasts alike.

The radiant is a hybrid: rectangular or square in shape (like the emerald cut), but with brilliant facets combining the strict geometry of step cuts with the scintillation of brilliant cuts. Invented in the 1970s, the radiant cut bridges clean geometric lines and maximum brilliance. It is ideal for those who love straight lines but desire an exceptional sparkle. It conceals inclusions more effectively than the Emerald cut, thanks to its fragmented facet arrangement.

The heart is the most symbolic of all diamond shapes. A variation of the round brilliant featuring a distinctive upper cleft, the heart requires expert cutting to preserve perfect symmetry and avoid a central bow-tie effect. It is rarely chosen for an engagement ring, appearing more often as a pendant, yet it remains an unmistakable declaration of intent. A heart-shaped diamond should be at least 0.50 carat for the shape to read clearly. Below that weight, the cleft becomes difficult to distinguish.

The shape refers to the diamond's external outline (round, oval, princess). The cut quality (cut grade) refers to the precision of proportions, angles, and polish. A perfectly cut round brilliant reflects incoming light directly back to the observer's eye, producing brilliance.

The facets are the polished flat surfaces of the diamond. The number of facets varies by shape: 58 for the round brilliant, 76 for the radiant, 71 for the princess. Yet the number alone guarantees nothing. The angle and arrangement of the facets determine the brilliance, fire, and scintillation.

Brilliance: the quantity of white light reflected. Fire: the dispersion of light into spectral colours. Scintillation: flashes of light visible as the diamond moves. Brilliant-cut shapes (round, oval, pear, marquise, modified cushion brilliant, princess, radiant) are designed to maximise these three qualities. Step-cut shapes (Emerald, Asscher) favour clarity and a mirror-like effect.

The solitaire places the diamond center stage. All shapes work beautifully, but the round brilliant remains the ultimate reference: its exceptional brilliance needs no embellishment. The oval, pear, and marquise create a more personal, less conventional look.

A halo of small diamonds surrounds the center stone. Rounded shapes (round, oval, cushion) lend themselves naturally to a circular halo. The princess and radiant cuts call for a square or rectangular halo to honor their geometric lines.

The trilogy setting aligns three stones, typically a central diamond flanked by two smaller ones. The round brilliant is the classic choice, but an emerald cut in a trilogy setting (with two lateral baguettes) exudes an unmatched Art Deco elegance.

Pave covers the band with small diamonds. The shape of the center stone matters less than its ability to stand apart from the pave. Taller shapes (round brilliant, cushion) create more contrast than flatter ones (emerald cut).

Vintage shapes (cushion, Asscher, emerald cut) naturally evoke bygone decades. Paired with intricately carved settings, they revive the aesthetic of the 1920s and 1940s.

18K Yellow Gold (75% pure gold) warms diamonds with a slight color tint (grades H to K). Vintage shapes (cushion, Asscher) harmonize naturally with yellow gold, evoking the spirit of antique jewellery.

18K White Gold (gold and palladium) and Platinum (95% pure) are the metals of choice for colorless diamonds (grades D to G). Their neutrality conceals no tint whatsoever. Platinum, being hypoallergenic, is the benchmark of medical-grade implants: zero allergenic risk. Worth noting: certain white gold formulations (older pieces or those produced outside the EU) may contain nickel, a potential allergen. Mayuri's 18K yellow gold is formulated without nickel (silver and copper only).

Rose gold (gold combined with 20 to 25% copper) creates a warm, striking contrast with white diamonds. Soft, rounded shapes (round brilliant, oval, cushion) pair especially beautifully with the warmth of rose gold.

The round brilliant commands a higher price per carat. The reason: its cut generates significant raw material loss (up to 50% of the original stone). Fancy shapes (oval, princess, cushion, Emerald cut, pear, marquise, Asscher, radiant, heart) cost 20 to 30% less at equivalent quality.

In practical terms: with a budget of $3,600, you can obtain a round brilliant of 0.70 carat or an oval of 0.90 carat, at comparable clarity and colour grades.

The shapes that maximise apparent carat size are the marquise, oval, and pear. Their extended table surface makes them appear larger at equal weight. The shapes that demand higher clarity are the Emerald cut and Asscher. Their broad, flat facets reveal every inclusion, making a VS2 grade the minimum recommended, or even VS1. The shapes that conceal inclusions are the round brilliant, modified brilliant cushion, radiant, and princess. Their fragmented facets scatter light and disguise internal flaws, meaning a well-selected SI1 grade (with the inclusion positioned away from the centre) can be entirely sufficient.

The round brilliant commands a higher price per carat. The reason: its cut generates a significant loss of rough material, up to 50% of the original stone. Fancy shapes (oval, princess, cushion, emerald, pear, marquise, Asscher, radiant, heart) cost 20 to 30% less at equivalent quality.

In practical terms: with a budget of $3,500, you can acquire a round brilliant of 0.70 carats or an oval of 0.90 carats, at comparable clarity and color grades.

The shapes that maximize apparent carat size are the marquise, oval, and pear. Their extended table surface makes them appear larger at equal weight. The shapes that demand high clarity are the emerald cut and Asscher. Their broad, flat facets reveal every inclusion. Budget accordingly: a VS2 minimum is recommended, ideally VS1. The shapes that conceal inclusions are the round brilliant, modified brilliant cushion, radiant, and princess. Their fragmented facets scatter light and mask internal flaws. A well-chosen SI1 grade, with the inclusion positioned away from the center, can be perfectly suitable.

Choosing a diamond shape means defining the visual identity of a ring worn for decades. The round brilliant remains the benchmark for its unmatched brilliance, yet each of the nine other shapes offers a distinct personality: the oval elongates the hand, the princess cut sparkles with intensity, the emerald cut radiates Art Deco elegance, and the marquise maximises the appearance of carat weight.

Several factors come into play: your budget (fancy shapes typically cost 20 to 30% less), your preferred setting style (solitaire, halo, trilogy), the visual effect on your hand (elongating versus compact shapes), and simply what speaks to you. A well-chosen diamond is not the one that ticks every technical box, but the one you will never tire of looking at.

Our creations incorporate shapes suited to each design, always set in 18K gold, always individually selected by our gemologists. Form follows function, never the other way around.

Choosing a diamond shape means defining the visual identity of a ring worn for decades. The round brilliant remains the ultimate reference for its exceptional brilliance, yet the nine other shapes each offer a distinct character: the oval elongates the hand, the princess scintillates with intensity, the emerald cut exudes Art Deco elegance, and the marquise maximizes apparent carat size.

The criteria naturally intersect: your budget (fancy shapes cost 20 to 30% less), your preferred setting style (solitaire, halo, trilogy), the visual effect on your hand (elongating versus compact shapes), and simply what speaks to you. The right diamond is not the one that checks every technical box; it is the one you will never tire of looking at.

Our creations incorporate shapes suited to each design, always set in 18K gold, always individually selected by our gemologists. Form follows function, never the other way around.