The cushion cut is a faceting style characterised by a square or rectangular outline with softly rounded corners and curved sides, producing a silhouette that resembles a bolster cushion or pillow. It is among the oldest standardised cutting forms still in widespread use, tracing a direct lineage to the old mine cut of the eighteenth and nineteenth centuries, and it remains one of the most commercially significant shapes in both the diamond and coloured-gemstone trades. Its enduring appeal rests on a combination of factors: the rounded corners reduce the risk of chipping at vulnerable points, the relatively deep pavilion retains carat weight from the rough, and the broad facet arrangement tends to saturate colour in transparent coloured stones rather than diluting it — a quality prized by cutters working with ruby, sapphire, spinel, and alexandrite.

Historical Development

The immediate ancestor of the modern cushion cut is the old mine cut, which dominated diamond fashioning from roughly the early 1700s until the late nineteenth century. Old mine cuts were shaped by hand on primitive scaifes and were guided by the natural octahedral form of diamond rough; the resulting stones had a high crown, a small table, a large culet, and an outline that was roughly square with rounded corners. The term "old mine" itself referred to the Brazilian and Indian alluvial sources then considered the premier origins, as opposed to the "new mines" of South Africa opened after 1867.

As steam-powered and later electric cutting machinery became available in the 1890s and early 1900s, cutters began transitioning toward the round brilliant, which offered superior optical performance under the gas and electric lighting that was replacing candlelight in fashionable interiors. The old mine cut's high crown and open culet, optimised for the warm, directional glow of candles — hence the alias candlelight cut — was less flattering under diffuse electric illumination. Nevertheless, the cushion outline never disappeared; it was simply refined. By the mid-twentieth century, the trade recognised two principal modern variants: the cushion brilliant, in which the pavilion facets radiate in a pattern closely analogous to a round brilliant, and the cushion modified brilliant, which incorporates an extra row of facets on the pavilion that produces a distinctive crushed-ice or sparkling-water visual effect.

Geometry and Proportions

A cushion cut is defined primarily by its outline rather than by a single prescribed facet arrangement, which distinguishes it from the round brilliant, where proportions are rigorously standardised. The key geometric parameter is the length-to-width ratio. A ratio of 1.00 produces a square cushion; ratios between approximately 1.10 and 1.20 yield a gently rectangular stone that many buyers find more elegant on the finger. Ratios above 1.25 are sometimes marketed as elongated or rectangular cushions and begin to approach the territory of the radiant cut.

Other proportions that influence appearance include:

• Table percentage — typically 55–65% in well-cut modern cushions, though antique-style cuts may have tables as small as 45%.
• Crown height — higher crowns (above 15% of total depth) produce more dispersion and a livelier, more antique character; lower crowns yield a flatter, more contemporary look.
• Pavilion depth — cushion cuts tend to carry more depth than round brilliants of equivalent face-up size, meaning that two stones of identical carat weight will show different spread depending on their cut style.
• Culet — antique-style reproductions often include a small faceted culet in homage to the old mine tradition; modern cushions typically have a pointed or very small culet.

The curved sides that define the cushion outline are not merely decorative: they distribute stress away from the corners, making the shape particularly suitable for stones with pronounced cleavage (such as topaz) or for large, expensive rough where corner chipping would represent a catastrophic loss.

Optical Character and the Cushion Modified Brilliant

The two principal pavilion arrangements produce markedly different visual effects. The cushion brilliant pavilion, with its main facets, lower girdle facets, and star facets arranged in a pattern derived from the round brilliant, produces broad, well-defined flashes of light and relatively clear reflections of the surrounding environment. Many buyers and cutters consider this the more classical expression of the shape.

The cushion modified brilliant — sometimes called a "modified cushion" in grading reports issued by the Gemological Institute of America — incorporates an additional row of small facets on the pavilion, often described as an extra set of lower girdle facets or a "French" pavilion arrangement. These additional facets break up reflections into numerous smaller, overlapping patches of light, creating the characteristic crushed-ice appearance. This effect can be visually spectacular in well-lit retail environments but may obscure the internal character of a coloured stone; for this reason, coloured-gemstone cutters more frequently favour the cushion brilliant arrangement, which allows the body colour to read cleanly.

The Cushion Cut in Coloured Gemstones

The cushion shape has long been the default choice for fine coloured stones, and a survey of important historical pieces confirms this. The Blue Belle of Asia, a 392.52-carat Ceylon sapphire sold at Christie's Geneva in 2014, is a cushion cut. The Crimson Flame spinel of 52.71 carats, also sold at Christie's, is cushion-cut. The majority of important Burmese rubies offered at auction over the past three decades have been cushion cuts, reflecting both the shape of the typical Mogok rough and the long-established preference of South and Southeast Asian jewellery traditions for this form.

The optical logic is straightforward. Coloured stones derive their value primarily from the richness and evenness of their body colour rather than from colourless dispersion (fire). A cushion brilliant's relatively large facets and moderately deep pavilion create long light paths through the stone, intensifying saturation. The rounded outline also minimises the "windowing" effect — the pale, washed-out zone visible through the table of poorly cut stones — by encouraging light to enter and exit at angles that interact with the colour-causing chromophores throughout the pavilion.

Cutters working with strongly pleochroic materials such as tanzanite, alexandrite, or iolite must orient the rough carefully before fashioning a cushion, since the shape's depth and broad table will emphasise whichever pleochroic direction is aligned with the optic axis. A tanzanite cushion oriented to show the blue-violet axis face-up will appear dramatically different from one oriented to show the burgundy axis.

The Modern Revival and Market Context

The cushion cut experienced a significant commercial resurgence beginning in the late 1990s and accelerating through the 2000s and 2010s, driven in part by a broader appetite for vintage-inspired jewellery aesthetics and in part by improvements in cutting technology that allowed the shape to be executed with greater optical precision than was possible by hand. By the early 2020s, the cushion cut had become the second most popular shape for diamond engagement rings in several major markets, trailing only the round brilliant.

In the coloured-gemstone trade, the cushion's dominance has been more continuous than cyclical. Fine sapphires, rubies, and spinels from Burmese, Ceylonese, and Tajik sources are routinely presented in cushion form, and gemmological laboratories — including the GIA, Gübelin Gem Lab, and SSEF — issue origin and treatment reports for cushion-cut stones as a matter of routine. When comparing prices per carat, buyers should be aware that a cushion cut will typically show less face-up spread than a round brilliant of equal weight, a consequence of the shape's greater depth; this is not a defect but an inherent characteristic of the form.

The term pillow cut is an informal synonym used occasionally in retail contexts; it carries no technical distinction from cushion cut. The term candlelight cut, while evocative, is largely historical and is rarely encountered in contemporary trade documentation.

Further Reading

• GIA — Understanding Diamond Cut
• GIA — Gems & Gemology (journal archive)
• International Gem Society — Cushion Cut Gems