From Round to Marquise: How to Choose Your Lab-Grown Diamond Shape

Diamond shape has always been personal, but in 2026 it is becoming even more expressive. On 2 October, the Financial Times reported growing interest in angular and unconventional diamond cuts, with designers using geometry to give jewellery a stronger point of view. Classic shapes are not disappearing; there is simply more freedom to choose a diamond for its silhouette, character and the way it works with your life.

Whether you are choosing an engagement ring, pendant or earrings, here is a practical guide to five enduring shapes.

Shape and cut are related — but not identical

“Shape” describes the outline seen from above: round, oval, pear, emerald or marquise. “Cut” can also describe the arrangement and proportions of a diamond’s facets, which influence how it handles light. GIA gives a formal cut grade only to round brilliant diamonds; other outlines are usually grouped as fancy shapes.

Two diamonds of the same shape and carat weight can still look very different. Look beyond the label and consider symmetry, proportions, brightness and how pleasing the individual stone appears to your eye.

Round: classic and versatile

The round brilliant is the familiar choice for good reason. Its balanced outline works easily in solitaires, clusters, hoops, studs and pendants, while its faceting is designed to return plenty of light.

Choose round if you like symmetry and timeless styling. It is also an excellent starting point if you want the diamond to feel classic while the setting, gold colour or surrounding stones provide the personality.

Oval: soft, modern and elongated

An oval keeps the curved elegance of a round diamond but adds length. GIA notes that elongated shapes can appear larger face-up than a round diamond of the same carat weight, although the effect varies with proportions.

When comparing stones, decide whether you prefer a softly rounded oval or a longer, slimmer one. Some ovals show a dark “bow-tie” area across the centre, so view the diamond in motion and in different lighting rather than relying on a single photograph.

Pear: graceful with a sense of direction

A pear shape combines a rounded end with one elegant point. It can feel romantic, contemporary or dramatic depending on its proportions and the direction in which it is worn.

Because the point is more vulnerable, GIA recommends a protective setting such as a V-prong or bezel. That is especially important for rings worn every day. In earrings and pendants, the teardrop silhouette creates a beautiful focal point without needing an elaborate design.

Emerald: clean lines and quieter light

Emerald-cut diamonds use long step facets rather than the many small facets associated with brilliant cuts. The result is a “hall of mirrors” effect: broad flashes of light, strong geometry and a calmer, more architectural appearance.

Those open facets also make clarity and colour easier to see, so compare emerald cuts carefully. Choose emerald if you are drawn to understatement, Art Deco references and strong lines rather than maximum sparkle.

Marquise: bold and distinctive

With two pointed ends, the marquise has one of the most recognisable diamond silhouettes. It can look vintage in a delicate setting or sharply modern when kept clean and minimal. Its elongated outline can also create the impression of greater face-up size.

Symmetry is particularly important: the points should align and both sides should feel balanced. The pointed ends benefit from protective V-prongs or another secure setting. A subtle bow-tie may also be visible, so inspect the diamond face-up and in movement.

Let your lifestyle guide the setting

The most fashionable shape is not automatically the best one for you. If you work with your hands, exercise in your jewellery or dislike pieces that catch easily, ask about a lower-profile or more protective setting. If maximum light and delicacy matter most, a fine prong setting may be your preference.

Judge the whole piece, not the centre stone alone. Band width, metal colour and setting height all change how a diamond shape reads.

Choose the gold that completes the design

Yellow gold adds warmth and contrast, white gold creates a crisp continuous look, and rose gold brings a softer finish. GeMMs & Co works in solid 9ct and 18ct gold: in UK hallmarking terms, 9ct gold carries a 375 fineness mark, while 18ct gold carries 750.

There is no universal “best” combination. A marquise in yellow gold can feel sculptural; an emerald cut in white gold can look exceptionally clean; a pear in rose gold can appear soft and romantic. The right answer is the one you will enjoy wearing.

A genuine diamond, shaped around you

Laboratory-grown diamonds are genuine diamonds. GIA states that they have essentially the same chemical composition, crystal structure, optical and physical properties as diamonds formed in nature; their origin is different and should always be clearly disclosed.

That gives you the freedom to begin with design: the outline you love, the gold colour you wear and the setting that suits your routine. At GeMMs & Co, genuine lab-grown diamonds are paired with solid 9ct and 18ct gold and London craftsmanship to create modern jewellery made for real life.

Explore GeMMs & Co and find the diamond shape that feels unmistakably yours.