Most Popular Diamond Shapes for Engagement Rings in 2026

Quick Answer — 2026 Trend Snapshot

Round brilliant still holds the top spot in 2026, at roughly 26% of engagement ring diamonds sold, but oval has closed in fast—now around 25%, according to The Knot’s 2026 Real Weddings study. Princess cut has fallen the furthest, down to about 8% after years as the No. 2 shape. Marquise, antique cuts (Old Mine, Old European, and rose), and elongated cushions are the shapes gaining the most ground year over year. This is a shift in what’s being asked for at the design stage, not a change in what makes a shape perform well—the guide below tracks both: where each shape stands in 2026 and the cut structure, brilliance, and price-per-carat behind it.

Diamond shape trends move slower than fashion, but they do move — and 2026 is a year with a clearer direction than most. This guide tracks what’s actually gaining and losing ground right now, and, shape by shape, what each one is built to do: how it scatters light, how large it reads on the hand, how it wears day to day, and what it costs per carat. A trend is only worth following if the shape behind it performs — this is where the two are checked against each other.

In this Guide

Planning a custom design? Every engagement ring at our Toronto studio starts with a conversation about shape, proportion, and how the diamond will sit on the hand. See our custom engagement ring process →

Oval

Brilliant cut · Ideal length-to-width ratio: 1.3–1.5:1

Oval has closed the gap with round faster than any other shape this decade — now around 25% of engagement ring diamonds, up from a fraction of that a few years ago, and reinforced by high-profile engagements including Cristiano Ronaldo’s proposal to Georgina Rodríguez with an oval-cut centre stone in 2025. It uses the same brilliant-cut facet structure as round, so it produces comparable fire and sparkle, but its elongated outline covers more visible surface area — an oval diamond will consistently face up larger than a round diamond of identical carat weight.

Proportion is the detail that separates a well-cut oval from an average one. Ovals cut outside the 1.3–1.5:1 length-to-width range can develop a “bow-tie” — a shadow that crosses the stone’s center under certain lighting. A well-proportioned oval controls this effect; a poorly cut one doesn’t.

Because ovals retain more of the rough diamond during cutting than round brilliants, they typically cost less per carat for equivalent color and clarity — a meaningful factor for anyone prioritizing size within a set budget.

Cushion

Brilliant or modified-brilliant cut · Rounded square or rectangular outline

Cushion cuts pair rounded corners with a square or rectangular outline — a shape that traces back to 19th-century cutting techniques and reads as noticeably softer than a round or princess cut. Standard cushions produce a warm, even brilliance; modified cushions add extra facets for a denser, “crushed ice” sparkle pattern.

Cushion’s deeper pavilion means it can face up smaller than a round or oval of the same carat weight, and it hides small inclusions well — its broad facets scatter light in a way that makes minor clarity flaws harder to spot with the naked eye.

Cushion is one of the shapes seeing the strongest renewed interest heading into 2026 — reinforced by recent high-profile cushion-cut engagement rings, including Miley Cyrus’s — largely because it bridges antique character with modern brilliance more directly than any other cut.

Emerald

Step cut · Rectangular, concentric facets

Emerald cut belongs to the step-cut family, built from long, rectangular facets arranged in parallel rows rather than the triangular facets of a brilliant cut. The result is a “hall of mirrors” light pattern—broad, flat flashes instead of scattered sparkle.

That open facet structure is unforgiving. Step cuts expose color and clarity directly, which is why emerald-cut diamonds generally need a higher starting grade — typically VS2 clarity or better and G color or better — to look clean face-up. In exchange, a well-selected emerald cut reads as clean and architectural in a way brilliant cuts don’t.

Emerald’s shallow depth and large table also mean it faces up larger for its carat weight than a round diamond, a practical advantage alongside its clean, minimal-decoration silhouette.

Radiant

70 facets · Brilliant-and-step hybrid · Cropped corners

Radiant combines a rectangular or square outline with a full brilliant-style facet pattern, making it the most brilliant of the shapes with straight sides. Where emerald favors clarity, radiant favors sparkle — its “crushed ice” surface pattern also does a better job than a step cut of masking small inclusions or a warmer color grade.

Radiant’s cropped corners aren’t a stylistic detail — they reduce the risk of chipping at points that would otherwise be exposed, making it one of the more durable rectangular shapes for daily wear.

Because it retains more of the rough diamond than a round cut, radiant is also one of the more cost-efficient shapes for buyers prioritizing carat size and brilliance together.

Marquise

Brilliant cut · Elongated, pointed ends

Marquise is an elongated brilliant cut that tapers to a point at both ends—a silhouette originally cut to maximize apparent surface area from a given amount of rough diamond. It remains one of the most efficient shapes for stretching carat weight across a visible surface: a well-cut marquise can appear noticeably larger than a round diamond of the same weight.

After several quieter years, marquise is building real momentum again for 2026—industry supplier data shows it among the shapes that increased the most in popularity over the past year, alongside emerald and elongated cushions—largely among buyers looking for a shape with a clearer point of view than round or oval offers.

Its pointed tips are the shape’s structural vulnerability. A protective setting — V-prongs or a burnished edge — is not optional; it’s what keeps those points from chipping under normal wear.

Pear

Brilliant cut · Teardrop, one rounded end and one point

Pear combines the rounded end of an oval with the tapered point of a marquise, and it’s one of the more versatile shapes on the hand — worn point toward the hand or point outward, depending on how the wearer wants the elongating effect to read.

Like oval and marquise, pear can develop a bow-tie effect if the length-to-width proportions and facet angles aren’t well matched, and its single point needs the same protective setting consideration as marquise.

Pear generally offers strong value per carat, retaining more rough material during cutting than a round brilliant, while still delivering comparable sparkle.

Princess

Brilliant cut · Square, sharp corners

Princess is a square modified brilliant—sharp, right-angle corners paired with a brilliant-style facet pattern beneath the surface. It’s the most brilliant of the shapes with straight edges, and its deep pavilion conceals inclusions unusually well. It’s also the shape that has lost the most ground: once the No. 2 diamond shape for engagement rings, princess now sits at around 8% of the market, as demand has shifted toward oval, cushion, and elongated silhouettes.

That same depth is also why a princess cut can look slightly smaller face-up than a round or oval of equal carat weight—more of the stone’s volume sits below the band, out of view. Its exposed corners require V-prong settings, without which they’re vulnerable to chipping.

Princess retains more of the original rough diamond in cutting than a round brilliant, making it one of the more cost-efficient shapes for equivalent quality.

Antique & Vintage Cuts

Old Mine · Old European · Rose cut · Hand-cut, high crown, small table

Old Mine, Old European, and rose cuts predate the modern round brilliant, and each was hand-cut using tools and light sources—candlelight, gas lamp—that no longer define how we shop for diamonds but still define how these cuts behave. Fewer, larger facets produce a softer, warmer glow instead of the sharp scintillation of a modern brilliant cut.

These are the clearest new movements in diamond shape for 2026—visible even at the highest-profile end of the market, where Taylor Swift’s engagement ring uses a large old mine brilliant center stone. More buyers are choosing character and asymmetry over uniform sparkle — a deliberate departure from the precision-cut standard that has dominated for the past century.

Antique cuts show color and clarity more openly than modern brilliant cuts, and true period stones are rare; most antique-style diamonds available today are newly cut to replicate the historical facet pattern rather than salvaged originals.

Why Cut Quality Matters More on Fancy Shapes

Cut and shape are often treated as the same decision. They aren’t. Shape is the outline—round, oval, emerald. Cut is the precision of the angles, proportions, and facet placement within that outline, and it’s the single factor with the most control over how a diamond performs.

GIA issues a standardized Cut grade—Excellent through Poor—for round brilliant diamonds only. That scale doesn’t exist for any fancy shape. An oval, cushion, or emerald cut diamond is instead evaluated on its individual proportions, symmetry, and polish, without a universal number to compare it against.

What this means for buyers: Two ovals of identical carat weight, color, and clarity can perform very differently depending on how they were cut. A poorly proportioned oval will bow-tie, look glassy, or face up smaller than expected. This is precisely why expert evaluation matters more on fancy shapes, not less—there’s no standardized grade to fall back on.

At Lumi Jewelry, every centre stone is assessed individually by our GIA Graduate Gemologist before it’s set — proportions, symmetry, and light return, checked against the specific setting the stone is going into. That step exists precisely because shape alone doesn’t guarantee performance.

Want the technical breakdown? Table percentage, depth percentage, crown and pavilion angles, and how GIA and HRD grade cut quality in full. Read the Diamond Cut Guide →

How to Choose Your Diamond Shape

Shape selection comes down to five structural questions, not a single aesthetic preference.

Light Behavior

Brilliant cuts scatter light into many small flashes. Step cuts and antique cuts produce fewer, broader flashes that put clarity and color on display rather than sparkle. Decide which effect matters more before narrowing down a shape.

Budget per Carat

Fancy shapes generally cost less per carat than round for equal carat weight and quality, since cutting them wastes less of the original rough diamond. This is where shape choice and budget intersect most directly.

Weighing a shape against your own lifestyle and style? Read our full guide to choosing the right shape for you →

Design Around the Right Shape

At Lumi Jewelry, choosing a diamond shape is the first step in a custom design process — not a checkbox before checkout. Our GIA Graduate Gemologist reviews centre stone options with you directly at Toronto studio prices with no retail markup.

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