Cushion Cut Diamonds: The Complete Buying Guide

The cushion cut is one of the oldest diamond shapes still widely used today, with roots in the old mine cuts of the 18th and 19th centuries. It has evolved considerably since then, but it retains the softly rounded corners and pillow-like silhouette that give the shape its name — and a romantic, slightly vintage character that no other shape quite replicates.

What Defines a Cushion Cut

A cushion cut diamond has a square or rectangular outline with rounded corners, distinguishing it from the sharp corners of a princess or radiant cut. Within this general shape, cushion cuts vary considerably in facet structure — more on this below — but the rounded-corner silhouette is consistent across all variations.

Cushions typically have larger facets than round brilliants, which produces a different kind of light play: less of the rapid, fine sparkle of a brilliant cut and more of a "chunky," broader sparkle often described as more dramatic or glowing in character. This makes cushion cuts particularly striking in candlelight or softer indoor lighting.

Cushion Brilliant vs Cushion Modified: A Critical Distinction

This is one of the most important and frequently overlooked aspects of buying a cushion cut. There are two primary facet structures, and they produce quite different appearances:

The cushion brilliant (also called a "chunky" cushion) has a facet arrangement similar to a round brilliant — larger, broader facets that produce that characteristic glowing, dramatic sparkle. This is the more classic cushion appearance and tends to be preferred by those who love the traditional cushion look.

The cushion modified brilliant has an additional row of facets (often producing an "extra facet" or "crushed ice" appearance under the table) that creates a finer, more scattered sparkle pattern, somewhat similar to an oval or pear modified brilliant. This style can look almost glittery or icy in direct light, and very different from the classic cushion look. Neither is superior, but the difference is substantial, and buyers who fall in love with one style may be disappointed by the other.

In grading reports, the distinction is noted — checking for "cushion brilliant" vs "cushion modified brilliant" on a GIA report, or asking your jeweller directly, is the clearest way to ensure you're getting the style you expect.

Proportions and the Squareness Spectrum

Cushion cuts range from nearly square (length-to-width ratios close to 1.00) to noticeably rectangular (ratios approaching 1.20 or above). A square cushion reads as compact and symmetrical; a rectangular cushion has an elongating effect similar to an oval, though more subtle. Most buyers tend toward the 1.05 to 1.15 range, which reads as a balanced square with just a hint of elongation.

As with ovals, the right proportions are personal. On the finger, the difference between a 1.05 and a 1.15 ratio stone is more noticeable than the numbers suggest — try both if possible.

Settings That Complement Cushion Cuts

Cushion cuts pair beautifully with vintage-style settings — the soft corners complement milgrain, filigree, and halo details in a way that feels cohesive and romantic. A round halo around a cushion centre stone creates a classic look (the square-inside-a-circle combination echoing Edwardian jewellery), while a cushion-shaped halo creates a more seamless, unified outline.

Four-prong settings that grip at the corners work well structurally for cushion cuts. Because the corners are rounded, they're less vulnerable to chipping than the sharp corners of a princess cut, making a lighter prong profile viable for most wearers.

What Cushion Cuts Do Particularly Well

The cushion cut's larger facets and broader sparkle tend to show colour and clarity more than a round brilliant, which is worth keeping in mind when selecting grades — opting for a slightly higher clarity grade than you might for a round can be worthwhile for a cushion if clarity characteristics (inclusions) are visible near the centre of the table. On the colour front, the shape tends to retain warmth, particularly in the body of the stone, so buyers who prioritise a bright white appearance sometimes choose a slightly higher colour grade than they would for a round.

A Shape With Genuine Character

The cushion cut's enduring appeal lies in what it offers that no modern brilliant shape can replicate: a connection to the romance and craft of earlier eras of jewellery, combined with a warmth of sparkle that feels genuinely different from the sharper brilliance of a round or princess cut. For couples drawn to that quality — that softer, more glowing light play — the cushion remains one of the most distinctive and personally meaningful shapes available.

Choosing between cushion brilliant and cushion modified is the kind of decision that's much easier to make in person. Book a consultation and we'll show you both side by side.