LAB GROWN & NATURAL DIAMONDS
DIAMOND SHAPES GUIDE
Choosing a diamond shape is one of the most personal decisions in the engagement ring journey. Each shape has its own character — the way it catches light, how it sits on the finger, and what it says about the person wearing it. At SJ Gems we offer all major diamond shapes in both lab grown and natural diamonds, IGI and GIA certified, at the best prices in South Africa. Use this guide to find the shape that feels like you, then explore each cut in detail.
Round
The world’s most brilliant diamond cut — engineered for maximum light return.
Oval
Elegant and elongating — looks larger face-up than a round of the same carat.
Emerald
A step-cut rectangle with a calm, mirror-like depth — timeless and understated.
Marquise
The longest shape in diamonds — maximises face-up size and flatters every hand.
Pear
A classic teardrop silhouette that elongates the finger beautifully.
Cushion
Soft corners, romantic feel — a vintage favourite with modern appeal.
Radiant
Trimmed corners, brilliant-cut facets — the most versatile fancy shape.
Princess
Bold square cut with brilliant-style sparkle and a modern edge.
How to choose your diamond shape
If size matters — and for many people it does — consider an oval, pear, or marquise. These elongated shapes spread their carat weight over a larger surface area, so they appear noticeably bigger than a round diamond of the same weight. A 1 carat oval can look up to 10% larger than a 1 carat round brilliant.
The round brilliant is the undisputed champion of sparkle, with 57 to 58 facets mathematically designed to reflect the maximum amount of light. Oval, cushion, and radiant cuts come close. Emerald and asscher cuts are step-cut shapes — they offer dramatic flashes of light rather than constant brilliance, which many people find equally beautiful.
Fancy shapes — oval, pear, cushion, emerald, marquise, radiant, and princess — are typically priced 10 to 30% lower per carat than round brilliants of the same quality. This is because fancy shapes waste less of the rough diamond crystal during cutting. It is one of the reasons oval and pear cuts have become so popular for engagement rings.
Elongated shapes — oval, pear, marquise, and radiant — visually lengthen the finger, which many people find flattering. Round and cushion shapes give a more classic, symmetrical look that sits beautifully in a solitaire or halo setting. If you have shorter fingers, an oval or pear is often recommended by jewellers to create the illusion of length.
Common questions about diamond shapes
Which diamond shape is the most popular?
The round brilliant is the most popular diamond shape in the world, accounting for roughly 60% of all diamond sales globally. Its popularity comes down to its unmatched brilliance — the 57-facet design is engineered to reflect more light than any other cut. For engagement rings in South Africa, round brilliants remain the top choice, followed closely by oval and cushion cuts.
Which diamond shape looks the biggest?
Marquise, oval, and pear shapes appear largest face-up for a given carat weight because their elongated outlines cover more surface area than a round diamond of the same weight. A 1 carat oval diamond can appear up to 10% larger than a 1 carat round brilliant. If you want maximum visual size for your budget, an oval or pear lab grown diamond is one of the best choices available.
Do lab grown diamonds come in all shapes?
Yes — lab grown diamonds are available in every shape that natural diamonds come in. Round brilliant, oval, emerald, pear, cushion, princess, radiant, and marquise are all available in lab grown form. The only difference between a lab grown and natural diamond is origin. Their physical, optical, and chemical properties are identical, and they are graded by the same internationally recognised laboratories — IGI and GIA.
Are fancy shape diamonds cheaper than round brilliants?
Generally yes. Fancy shapes — including oval, pear, cushion, emerald, marquise, radiant, and princess — are typically priced 10 to 30% lower per carat than a round brilliant of equivalent quality. This price difference exists because the cutting process for fancy shapes wastes less of the rough diamond crystal. Combined with the lower base price of lab grown diamonds, a fancy shape lab diamond offers exceptional value for engagement ring buyers.
Which diamond shape is best for an engagement ring?
The best diamond shape for an engagement ring is the one that suits the person wearing it. Round brilliants are the classic choice and never go out of style. Oval and pear shapes are currently very popular for their elongating effect and larger face-up appearance. Cushion cuts have a romantic, vintage quality. Emerald cuts suit people who prefer understated elegance. At SJ Gems we are happy to guide you through the options — the right shape is a personal choice, and there is no wrong answer.
Ready to find your diamond?
Browse our full collection of IGI and GIA certified diamonds in all shapes —
lab grown and natural, at South Africa’s best prices.
Not sure where to start? Contact us — we’re here to help you find exactly what you’re looking for.