Shopping for a diamond can feel like learning a new language, especially when salespeople use “cut” and “shape” as if they are interchangeable. Shape is simply the outline you see—round, oval, emerald and so on—whereas cut is the precise geometry of every facet inside that outline. Get the cut right and light races through the stone, bounces back to your eye and creates the unmistakable fire that turns heads. Get it wrong and even a large, colourless diamond can look sleepy, while your budget quietly slips away on wasted carat weight.

This guide strips away the jargon and puts sparkle first. You will meet the 12 most popular shapes, discover how each balances brilliance, price and style, and pick up practical tips to keep any diamond dancing with light long after it leaves the jeweller’s bench. Whether you are choosing an engagement ring, upgrading a family heirloom or simply curious, the next sections will help you spend wisely and shine confidently.

1. Round Brilliant Cut

Still the gold standard among the different diamond cuts, the round brilliant has been mathematically tuned for maximum fire, scintillation and white-light return. Its perfect symmetry means even a half-carat stone can out-sparkle larger fancy shapes.

Sparkle & Facets

58 precisely positioned facets (including the culet) act like tiny mirrors, bouncing light back to the eye. Stick to GIA “Excellent” or AGS “Ideal” cut grades for guaranteed dazzle.

Ideal Proportions

• Table: 55–58 %
• Total depth: 59–62.5 %
• Girdle: thin to slightly thick
• Crown angle: ~34–35°

Style & Setting Ideas

Classic six-prong solitaires flaunt the outline, hidden-halo designs boost visual size, while pavé shoulders add extra shimmer without dominating the centre stone.

Pros, Cons & Budget Notes

• Brightest cut on the market
• Easy to match with straight wedding bands
  − Carries a 20–30 % price premium per carat
  − Demand for top grades limits bargain hunting

2. Princess Cut (Square Brilliant)

Second to the round in popularity, the princess cut offers a contemporary square outline without sacrificing sparkle. Born in the 1970s, its tiered pavilion keeps light ricocheting inside while the flat crown creates a sleek surface for modern ring designs.

Key Visual Features

Perfect square or razor-sharp rectangle, brilliant facet pattern radiates from centre, creating cross-shaped flashes.

Durability & Settings

Because its corners are delicate, a four-prong V-claw or bezel is non-negotiable for wear.

Value & Sparkle Balance

Great rough yield makes princess about ten percent cheaper per carat than round yet still bright, especially in GIA Very Good–Excellent cuts.

3. Cushion Cut

The cushion sits at the sweet spot between antique romance and modern brilliance. Rounded corners soften the outline, while a deep pavilion delivers warm, chunky flashes often called “candlelight” fire. Because cutters lose less rough than with a round, cushions frequently cost a little less per carat, letting you nudge the budget up on colour or carat weight if desired.

The Two Cushion Families

• Cushion Brilliant: larger facets, sharp “X” pattern, bold flashes – ideal when you crave sparkle close to a round.
• Cushion Modified (“crushed-ice”): extra pavilion facets break light into pin-fire glitter that hides inclusions well.

Ratios & Face-Up Size

A square look sits at a 1.00 ratio, while 1.10–1.20 elongates the stone and slims the finger. Cushions carry depth, so a 1 ct cushion faces up smaller than a 1 ct oval, but proper claw placement can disguise this.

Vintage Charm & Modern Twists

Halo borders underscore the pillowy outline; split-shank or bezel frames give Art-Deco vibes. For a contemporary edge, set an elongated cushion east-west or pair it with tapered baguette side stones.

4. Oval Cut

Oval diamonds keep the brilliant facet pattern of a round but stretch the outline into an elegant ellipse, giving finger coverage at a lower price-per-millimetre.

Why Ovals Look Bigger

An oval faces up 10 % larger than a same-carat round. The shape draws the eye lengthways, elongating the finger.

Bow-Tie Effect Management

A slight bow-tie shadow is unavoidable. View stones in daylight; pick one where the strip softens and flashes as you rock the gem.

Best Colour & Clarity Ranges

SI1–VS2 is generally eye-clean. Choose H+ in platinum, or drop to J in yellow or rose gold where warmth blends with the metal.

5. Emerald Cut

Sleek and understated, the emerald cut swaps disco-ball glitter for crisp, architectural flashes. Its elongated outline flatters most hands and usually costs less per carat than a round of equal quality.

Step-Cut Brilliance

Fifty-seven step facets create parallel “hall-of-mirrors” reflections, giving broad, dramatic flashes rather than pin-fire scintillation.

Clarity Matters

The wide, open table makes inclusions obvious—aim for VS2 or better in stones over 1 ct, or an eye-clean SI1 if you can inspect in person.

Sleek, Art-Deco Styling

Bezel settings, baguette side-stones or an east-west mount accentuate its refined, 1920s vibe without compromising durability.

6. Asscher Cut

Instantly recognisable by its concentric squares, the Asscher is essentially a square emerald cut perfected for Art-Deco lovers.

Square Step-Cut Geometry

Deep pavilion and high crown create a bold “windmill” pattern; eight equal sides make halo alignment effortless.

Hall-of-Mirrors Fire vs Weight

Smaller face-up than rounds, but step facets give broad flashes; price often 5–10 % lower per carat.

Setting Compatibility

Double claws or a vintage bezel protect the cropped corners; Asschers pair beautifully with trapezoid or baguette side stones.

7. Radiant Cut

Invented in 1977, the radiant cut combines the dazzling facet pattern of a round with the sleek outline of an emerald, producing a lively, contemporary shape that flatters most hands.

Hybrid Cut Science

70 brilliant facets plus cropped corners explode light while hiding colour better than traditional step cuts.

Rectangle vs Square Radiant

Aim for a 1.05–1.30 length-to-width ratio to create a finger-lengthening rectangle; 1.00–1.05 keeps a balanced, square profile perfect for halos.

Durability & Versatility

Trimmed corners resist knocks, so four-prong or bezel settings suit active lifestyles; radiants also slot smoothly into channel or pavé bands.

8. Pear Cut

Half round, half marquise, the pear (or teardrop) cut offers brilliant sparkle with a flattering, finger-lengthening outline that disguises weight at the tip.

Anatomy & Symmetry

58 facets broken into “head”, “belly” and pointed tip. Check for perfectly centred apex, even shoulders and a smooth outline—any wonkiness is impossible to hide once set.

Bow-Tie Awareness

Most pears show a faint bow-tie shadow; tilt the stone under daylight and spot-lighting, rejecting stones where a dark band stays static.

Style & Illusion Tricks

Wear the point towards the fingertip for a slimming effect. A halo evens out any slight asymmetry, while a five-prong or full bezel shields the vulnerable tip.

9. Marquise Cut

The marquise, instantly recognised by its two pointed ends, offers regal drama and generous finger coverage at surprisingly modest carat weights. It remains a standout among different diamond cuts.

Maximising Carat Spread

A 1 ct marquise measures roughly 10 × 5 mm, appearing up to 15 % larger face-up than a round of the same weight.

Football-Shape Care

Both tips are chip-prone; use V-prongs or a bezel and remove during sport.

Vintage Royal Heritage

Tapered baguette side stones echo its curves, while bezel settings modernise a historically opulent shape.

10. Heart Cut

A heart-shaped diamond delivers an unmistakable message of love, but its complex outline means only well-proportioned stones look crisp and balanced.

Sentimental Symbolism

Look for equal, rounded lobes, sharp cleft and defined point — anything else feels off-centre.

Clarity & Colour Guidance

The brilliant facet plan masks minor inclusions; stick to H+ colour so the lobes stay bright, especially in white metals.

Setting Tips

Five-prong baskets guard the point; halos and bezels amplify the outline and boost finger coverage.

11. Trillion (Triangular Brilliant) Cut

With three equal sides and razor-sharp brilliance, the trillion cut brings a futuristic vibe to jewellery.

Modern, Edgy Sparkle

31–50 facets throw flash-fire sparkle and the shallow depth makes the stone look larger per carat.

Use as Centre or Side Stones

A solo trillion centre shouts modern; matching pairs are perfect wings beside a round or oval in three-stone rings.

Handling Fragile Corners

Protect the knife-edge points with V-prongs or a bezel and take the ring off for sport to avoid chips.

12. Baguette Cut

Baguette diamonds offer architectural elegance; slim rectangles that emphasise clarity over disco-ball brilliance.

Slim Step-Cut Lines

14 step facets give mirror flashes; any body colour shows easily.

Popular as Accents or Eternity Bands

Low profile hugs the shank—ideal for channel shoulders, vintage three-stones or full eternity bands.

Buying Considerations

Look for VS clarity, straight edges and matching length-to-width ratios when buying multiples; slight J–K colour is acceptable beside yellow gold.

13. Sparkle Tips for Every Cut

Sparkle isn’t a happy accident; it’s the result of smart choices and regular TLC. Follow these universal pointers and every diamond will perform at its brightest.

Cut Grade Is King

Of the 4Cs, cut trumps the rest for light return. Always insist on GIA ‘Excellent’ or AGS ‘Ideal’; anything lower leaves light—and money—on the table.

Regular Cleaning Routine

Daily hand creams and soap films dim fire fast. Weekly: soak in warm water + drop of mild dish liquid, gentle toothbrush, rinse, pat dry with lint-free cloth.

Setting Maintenance

Loose prongs shift stone angles, cutting sparkle. Book a jeweller’s inspection once a year; A Star Diamonds does this gratis for UK customers.

Lighting & Photography Hacks

Diamonds love mixed lighting. Spotlights show rainbow fire, soft daylight reveals scintillation. When taking photos, angle stone 15–20° off camera to avoid dull grey ‘dead-zones’.

14. How to Choose the Right Diamond Cut for Your Hand, Style & Budget

With dozens of different diamond cuts sparkling back at you, the quickest path to a confident decision is to think practically before you think romantically. Use the checkpoints below as a filter and half the showcase will instantly rule itself out—saving both time and money.

Finger & Hand Proportions

Long fingers handle rounds, squares and chunky Asschers without looking crowded, while shorter or slender hands benefit from elongating shapes such as oval, marquise or pear that create elegant visual length.

Lifestyle & Durability Factors

If you lift weights, garden or work with tools, protect vulnerable points: choose bezel-set radiants, ovals or rounds over princess, marquise or trillion cuts whose sharp corners can chip.

Budget Optimisation

Fancy shapes often cost 10–30 % less per carat than rounds because cutters retain more rough. A cushion or emerald cut lets you nudge up carat or colour without stretching the wallet.

Matching Metal Colours

Cool platinum exaggerates any yellow tint, so stay at H or higher; warm yellow or rose gold masks J–K tones and pairs beautifully with vintage-leaning step cuts.

15. Diamond Cut FAQs Answered

Quick-fire answers to the most common questions about different diamond cuts:

What cut gives the most sparkle?

Round brilliant. Its 58 facets and perfect symmetry deliver the highest light return.

Which diamond cut is most affordable?

Cushion and princess. Efficient rough yield means 10–20 % less per carat than rounds.

Does cut affect diamond price more than carat?

Often. A 1 ct Excellent cut can outprice and outshine a poorly cut 1.2 ct by 30 %+.

Are certain cuts better for lab-grown vs natural diamonds?

Fancy shapes (oval, radiant, emerald) showcase lab-grown clarity while sidestepping the fluorescence sometimes seen in round lab stones.

Next Steps to Find Your Perfect Sparkle

Cut and shape decide how bright a diamond looks and how happy your wallet feels. If you’d like to compare shapes side-by-side and sketch a bespoke ring, book a free, no-pressure consultation with the gemologists at A Star Diamonds today.