Diamond Shapes and Cuts Explained: A Guide to All 10 Popular Cuts

Shape is the first thing anyone notices about a diamond, and it quietly drives everything else — how much it sparkles, how well it hides colour and inclusions, and how far your budget stretches. Here is how the ten most popular cuts actually behave.

Round brilliant — the benchmark

The round brilliant is engineered for maximum light return. Its 57 or 58 facets are arranged to bounce light back at your eye, which is why it out-sparkles every other shape and forgives a slightly lower colour grade. That brilliance also helps mask small inclusions. The catch is price: rounds command a premium because they sparkle best and waste the most rough during cutting. If sparkle is the priority and budget allows, this is the safe default.

Princess — modern and sharp

A square brilliant cut, the princess delivers near-round levels of fire with crisp, contemporary corners. It hides inclusions well but shows colour at the pointed corners, so don't drop too low on the colour grade. It uses rough efficiently, which makes it noticeably cheaper than a round of the same weight.

Oval — bigger for the money

An elongated brilliant, the oval carries its weight across a larger face-up area, so it reads bigger than a round of the same carat. It sparkles brilliantly and flatters the finger by lengthening it. Watch for the "bow-tie," a dark shadow across the centre — a well-cut oval keeps it faint.

Emerald — the step-cut showstopper

The emerald cut uses long, parallel facets (step cuts) instead of brilliant facets, producing a hall-of-mirrors flash rather than fire. That openness is honest: it shows inclusions and colour more readily than any brilliant, so prioritise clarity (VS or better) and a higher colour grade. In return you get an elegant, understated stone at a friendlier price per carat.

Cushion — soft and romantic

A square or rectangle with rounded corners, the cushion blends vintage charm with strong fire. It handles colour and inclusions reasonably well and tends to glow warmly, which is why it pairs beautifully with yellow and rose gold. Generally priced below a round.

Pear — the teardrop

Half round brilliant, half marquise, the pear is brilliant and elongating. The point shows colour, and like the oval it can carry a bow-tie, so cut quality matters. It looks larger for its weight and sits comfortably below round pricing.

Marquise — maximum spread

The marquise has the largest face-up area of any shape per carat, so it looks the biggest for the money. Its two points are vulnerable and concentrate colour, and the bow-tie risk is real. A dramatic, finger-lengthening choice for buyers chasing visible size.

Radiant — brilliance with corners

A brilliant-faceted rectangle with cropped corners, the radiant combines the sparkle of a round with the silhouette of an emerald. It hides inclusions and colour well thanks to its brilliant faceting, making it a forgiving, lively pick at a moderate price.

Asscher — the art-deco emerald

A square step cut with deep, concentric facets, the asscher shares the emerald's transparency and "windmill" pattern. It demands good clarity and colour for the same reason, and it suits anyone after a vintage, geometric look. Priced similarly to the emerald.

Heart — the statement

Essentially a pear with a cleft, the heart is a brilliant cut that needs skilled symmetry to read clearly — both lobes must match. Below about 0.50ct the shape gets hard to recognise, so it works best larger. A romantic, unmistakable choice.

How to choose

• Want the most sparkle? Round, then oval or radiant.
• Want size for your money? Marquise, oval or pear.
• Love a clean, elegant look? Emerald or asscher — but pay up for clarity and colour.
• Want vintage warmth? Cushion.

Whatever shape you fall for, the grade on the report should match what your eye and budget expect. A Diamonds Tester verification confirms the cut and quality are exactly what you are paying for before the ring goes on the finger.