Which lab grown diamond shape is best?
There is no single "best" diamond shape — the right one depends on the look you love, the finger it will sit on and how much sparkle or size you want for your budget. As a quick guide: round brilliant gives the most fire and is the safe classic; oval and pear look larger for their carat weight and elongate the finger; emerald and cushion trade some sparkle for a refined, vintage character. Because every Infinite Gems lab grown diamond is IGI Certified and physically identical to a mined diamond, you choose purely on style — and pay up to 90% less than the natural equivalent, so a larger or fancier shape stays within reach.
A diamond's shape (its outline — round, oval, square) is not quite the same as its cut (how well its facets are proportioned to return light). Shape is a matter of taste; cut quality is a matter of grading. This guide covers shape selection; every stone we set is cut to return maximum brilliance for its outline.
The 10 diamond shapes at a glance
Round brilliant. The most popular shape by far, and the most sparkling. Its 57–58 facets are engineered to maximise the return of light, so a round diamond hides small inclusions and colour tinge better than any other shape. It is the classic choice for a solitaire engagement ring, and pairs beautifully with a hidden halo. Because demand is highest and more rough is lost in cutting, round tends to cost a little more per carat than fancy shapes — though on a lab grown stone that difference is modest.
Oval. An elongated brilliant cut with the same fiery sparkle as a round, but a silhouette that looks noticeably larger for the same carat weight and slims and lengthens the finger. Oval has been one of the most-requested engagement shapes for several years running. Watch for the faint "bow-tie" shadow across the centre — on a well-cut oval it is minimal, and every oval we set is chosen to keep it subtle.
Emerald. A rectangular step cut with long, open facets that create dramatic flashes of light rather than sparkle, and a wonderful sense of clarity and depth — like looking into clear water. Because those open facets are so revealing, emerald cuts reward higher clarity, which is exactly why our centre stones are graded VVS2. Elegant, architectural and understated; a favourite for those who find round "too expected".
Cushion. A soft square or rectangle with rounded corners — a pillow shape. It blends vintage romance with plenty of brilliance, and its rounded corners are practical and snag-resistant for everyday wear. Cushion cuts hold light in a chunkier, more romantic way than a round and suit both solitaire and halo settings.
Princess. A sharp, contemporary square brilliant with striking corner-to-corner fire. It offers near-round levels of sparkle in a modern geometric outline and generally costs less per carat than a round. The pointed corners benefit from a protective setting.
Pear. A "teardrop" — a brilliant cut that is round at one end and pointed at the other. Worn with the point toward the hand, it elongates the finger like an oval while adding individuality. Popular for pendants and drop earrings as well as rings.
Marquise. A long, pointed ellipse ("boat" shape) that maximises apparent size — a marquise carries the largest face-up area per carat of any shape, so it looks impressively large and dramatically slims the finger.
Radiant. A rectangular or square outline with cut (brilliant-faceted) corners, combining the crisp shape of an emerald with the sparkle of a round. It is a superb bridge for anyone torn between step-cut elegance and brilliant-cut fire, and it flatters colour beautifully.
Asscher. A square step cut — essentially a square emerald — with concentric, "hall-of-mirrors" facets and a vintage Art Deco character. Like the emerald, it rewards high clarity, which our VVS2 centre stones deliver.
Heart. A romantic brilliant cut, effectively a pear with a cleft. It demands skilled cutting for perfect symmetry and is a favourite for pendants and statement gifts.
Which diamond shape looks the biggest?
If maximising visual size is the goal, elongated shapes win. Marquise, pear, oval and emerald all carry more of their weight across the face-up surface than a round or a princess of the same carat, so they read as larger on the hand. Elongated shapes also make fingers look longer and more slender. A round or cushion of the same carat will look a touch smaller but returns more sparkle. Because you are choosing a lab grown diamond, the more affordable path to a "bigger look" is simply to size up: our standard carat ladder runs from 1.0ct to 5.0ct, and the up-to-90% saving versus mined stones means a full carat more is often within the same budget.
Which shape flatters my hand?
Longer, narrower shapes — oval, pear, marquise, emerald — visually lengthen shorter or wider fingers and are a reliable flattering choice. Round, cushion and princess suit long, slender fingers and give a balanced, classic proportion. For smaller hands, an elongated shape adds elegance without overwhelming; for a bolder statement, a wide radiant or cushion fills the finger. There are no rules, only guidelines — the shape you are drawn to is rarely the wrong one, and our team is happy to talk options through before you decide.
Shape and the 4Cs: what to prioritise
The shape you choose changes which of the 4Cs matters most. Step cuts (emerald, Asscher) have large open facets that reveal inclusions and colour, so clarity and colour carry more weight — our VVS2 centre-stone standard is well suited here. Brilliant cuts (round, oval, cushion, pear, princess) scatter light and hide small inclusions, so you can prioritise carat and cut. Across every shape, our rings with a main diamond are set with an E colour, VVS2 clarity centre stone (IGI Certified for the Main Diamond), while multi-stone and pavé designs use D–F colour, VVS–VS clarity stones — grades chosen so the diamond looks bright and white whatever its outline.
Frequently asked questions
What is the most popular lab grown diamond shape?
Round brilliant remains the single most popular shape because it delivers the most sparkle and suits almost every setting, from a plain solitaire to a halo. Oval is a very close second and has been the fastest-growing shape for engagement rings, prized for looking larger than its carat weight and for elongating the finger. Between them, round and oval account for the majority of engagement-ring choices. That said, popular and right for you are not the same — the best shape is the one whose character you love and will still love in twenty years.
Do different diamond shapes cost different amounts?
Yes. Round brilliant usually costs the most per carat because it is in the highest demand and more of the rough crystal is lost in cutting to achieve its proportions. Fancy shapes — oval, pear, emerald, cushion and the rest — generally cost less per carat because cutting them wastes less material. On a lab grown diamond these differences are far smaller than on a mined stone, and because you save up to 90% versus a natural diamond overall, shape has only a modest effect on your final budget.
Which diamond shape looks the largest for the price?
Elongated shapes look biggest for their carat weight. Marquise has the largest face-up area of any shape, followed by pear, oval and emerald, so they appear larger on the finger than a round or princess of identical weight. If a big look matters most, choose an elongated shape and a slightly higher carat — with lab grown pricing, sizing up is affordable in a way it rarely is with mined diamonds.
Is shape the same as cut?
Not quite. Shape describes the outline of the diamond — round, oval, emerald, and so on. Cut describes how precisely the facets are proportioned and finished to return light, and it is graded (Excellent, Very Good, and so on) only for round diamonds; fancy shapes are assessed on symmetry and polish instead. A beautiful shape still needs a good cut to sparkle, which is why every Infinite Gems stone is selected for light performance, not outline alone.
Which diamond shape is best for everyday wear?
Shapes with no sharp points or with protected corners handle daily life best. Round, oval, cushion and radiant have either curved outlines or cut corners that resist chipping and snagging, making them ideal for a ring worn every day. Pointed shapes such as marquise, pear and princess are perfectly durable but benefit from a setting that shields their tips — a simple prong or bezel does the job. Whatever the shape, a lab grown diamond is a true 10 on the Mohs scale, exactly as hard as a mined diamond.
Written by Yoki, Infinite Gems — lab grown diamond and fine jewellery specialists. Every diamond is IGI Certified; certificate available upon request. Prices and availability vary by design; contact our team for a personalised quote.