Diamond guide
Diamond shapes guide
Kiran cuts ten shapes. Each has its own character and a typical length-to-width ratio that sets how long or square it reads on the hand.
| Shape | Character | L/W |
|---|---|---|
| Round brilliant | The reference cut, engineered for maximum brilliance and fire. | 1.00 |
| Oval | Brilliant sparkle in an elongated outline; looks larger for its weight and flatters the hand. | 1.33 – 1.50 |
| Cushion | A rounded square with soft corners; romantic, vintage, with strong fire. | 1.00 – 1.15 |
| Princess | A square brilliant; sharp, modern and very lively. | 1.00 – 1.05 |
| Emerald | A rectangular step cut with long facets and an understated, sophisticated look. | 1.30 – 1.50 |
| Pear | A teardrop with a brilliant point and a rounded end; elegant and elongating. | 1.45 – 1.70 |
| Radiant | A trimmed-corner rectangle with brilliant facets, between emerald shape and round sparkle. | 1.05 – 1.35 |
| Marquise | An elongated shape with pointed ends that maximises perceived size. | 1.85 – 2.15 |
| Asscher | A square step cut with art-deco character and concentric facets. | 1.00 – 1.05 |
| Heart | A brilliant cut of romance, where symmetry is everything. | 0.95 – 1.05 |
Choosing a shape
Length-to-width ratio is a matter of taste: a higher ratio reads as longer and more dramatic, a ratio near 1.0 as classic and balanced. Elongated shapes such as oval, marquise and pear make a finger look longer and a stone look larger. Step cuts such as emerald and Asscher show clarity more openly, so they reward a cleaner grade.
What shape means for price and turn
Shape is a commercial decision as much as an aesthetic one. Round brilliants sacrifice more rough in cutting and hold the steadiest demand, so they price highest per carat and turn fastest. Fancy shapes use rough more efficiently and usually buy softer, which is where a retailer can build margin without moving color or clarity. Oval leads current demand; emerald and cushion have strengthened; marquise and heart are specialist calls that reward stocking to order rather than to shelf.
Because shape drives face-up size, two stones of equal carat and grade can look a full size apart, and buy at different prices. This is why seasoned buyers work from the actual stone and its measurements, not the carat weight alone.
From shape to stone
Approved retailers filter the loose-diamond inventory by shape and length-to-width, review measurements and light performance, and take the stone straight into the ring builder at account pricing. Request trade access to begin, or read the 4Cs guide for how the grades interact with shape.
Common questions
Which diamond shape looks the largest for its carat weight?
Elongated shapes read largest face-up. Oval, marquise and pear spread more than a round of equal weight, so they look bigger on the hand. A well-proportioned round still returns the most light, so the choice trades spread against brilliance.
Why is a round brilliant more expensive than a fancy shape?
Rounds waste more rough in cutting and carry the steadiest demand, so their price per carat sits highest. Fancy shapes such as oval, cushion and emerald use rough more efficiently and usually buy at a lower price per carat for the same color and clarity.
What is the bow-tie in an oval or pear?
A dark band across the center caused by light leaking through the stone. A faint bow-tie is normal; a heavy one dulls the middle of the stone. It is a face-up judgment, not something a report grade captures, so these shapes reward reviewing the actual stone.
Which shapes show inclusions and color most?
Step cuts, emerald and Asscher, have long open facets that reveal clarity and body color more openly, so they reward a cleaner grade. Brilliant cuts scatter light and hide more, which lets a lower clarity or color sit face-up cleanly.
