Cut is an invisible artistry that brings a diamond to life.
Diamond cut refers to how well a diamond’s facets interact and reflect light.
Your Diamonds brilliance, its fire, its sparkle, all result to a perfect cut. In gemmology, cut is widely regarded as the most important (and most recommended) of the 4Cs. It's the only characteristic entirely in human hands, where nature determines colour, clarity, and carat weight, but cut is pure craftsmanship. Cut transforms a natural stone into a brilliant sparkly diamond.
What Is a Diamond Cut
Cut is the soul. Sparkle is the result.
Diamond cut refers to how well a diamond has been faceted, the precision of its angles, proportions, symmetry and polish.
Cut vs. Shape: Let’s Be Clear Here
Let's start with what trips everyone up. Diamond Cut is not the same as Diamond Shape. Diamond shape refers to the outline - round, oval, emerald, pear and so on. Diamond cut refers to how well the stone has been faceted, polished and engineered to reflect the light. Shape is about silhouette style. Cut is about sparkle.
Why Diamond Cut Matters most
Diamonds are optical treasures. Their beauty comes from the way they reflect and refract light. A perfectly cut diamond allows light to enter through the top, bounce between internal facets and reflect back through the top crown to your eye. This creates three visual effects: Brilliance, Fire and Scintillation. This is why cut determines your diamond's entire personality.
How Cut makes The Difference
A perfect cut enhances every other quality of a diamond. It can dramatically increase sparkle, can make a diamond appear whiter, can create the illusion of greater size, can make its inclusions less noticeable. A beautifully cut 0.75 carat diamond will outshine a poorly cut 1.00 carat stone. Which means a poorly cut diamond leaks out light from its sides or bottom, and the stone looks dull despite its size or clarity.
Excellent Cut means Excellent Brilliance
A diamond's beauty comes down to three elements: brilliance, fire, and scintillation – They are the trio of sparkle that enhances a diamonds brilliance.
Brilliance: is Brightness. You will see the brightness when white light is reflected back through the table to your eye – it is a diamond's baseline glow, the foundation of everything.
Fire or Dispersion: is the colours of hue. It is light splitting into rainbow hues as it passes through the stone. You'll see flashes dancing across the facets. The balance matters - too much and it's a disco ball; too little and the stone feels flat.
Scintillation: is the sparkle. The pattern of how a diamond glistens and twinkles as you move your hand. This makes a diamond lively, gives its personality. A perfect cut diamond will emanate light
from every angle.
The Blueprint of a Diamond
A diamond is made up of a carefully engineered arrangement of facets, each with a specific role to play. Just to simplify this, a diamond has two main sections. The crown - is top section sits above the widest point, and the pavilion – which is the lower angled section, both separated by a narrow band called girdle. And there are eight types of facets that make up diamonds cut.
- Table: The large tabletop facet that allows light to enter the stone.
- Star facets: The triangular facets surrounding the table.
- Bezel facets: The main crown facets that bend and disperse light.
- Upper girdle facets: Support light movement through the crown.
- Girdle: The narrow band around the widest point of the diamond.
- Lower girdle facets: Direct light through the pavilion.
- Pavilion: The lower section where internal reflection occurs.
- Culet: The small facet at the very bottom tip.
Imagine the table as a window letting light in, the crown as a steering mechanism, and the pavilion as a mirror system bouncing light back up and out. A well-cut diamond allows light to reflect back through the crown and table to you. When these proportions work together properly, the magic happens; there is brilliance!
Inside an Excellent Cut - The Seven Wonders of Brilliance
Table Size: The Light Gateway
Table size determines how much light flow through the diamond. The higher the percentage, the larger the table looks; the lower, the smaller. This is your diamond's light gateway, taking in natural light and reflecting it back as white brilliance and rainbow fire.
Look for 53 ~ 58%, balancing light entry for excellent performance and value. Premium Super-ideal cuts range from 54 ~ 57%. Under 53% appears dim with reduced sparkle; over 60% looks flat and glassy with less fire.
Depth Percentage: The Height Factor
Depth percentage is the stone's height divided by its width; simply how tall your diamond is. The higher the number, the deeper the stone; the lower, the shallower. This determines whether light bounces back to your eye. A shallow diamonds leak light out the bottom or sides. Deep diamonds trap light inside and appear dark or small
The ideal range is 59 ~ 62.5%, with premium super-ideals at 60 ~ 62.3%. Under 59% creates "fisheye" effect as light escapes the bottom. Over 63% traps light inside, causing "nailhead" darkness and making diamonds look smaller.
Crown and Pavilion Angles: The Precision Reflectors
Crown and pavilion angles work as a precision optical system. The pavilion acts as mirror and prism, reflecting light and directing back through the crown for maximum return and fire. These angles must pair perfectly, like a steeper crown balances with a shallower pavilion, or vice versa.
Your sweet spot: crown 34 ~ 35.5° with pavilion 40.6 ~ 41°. Premium Hearts and Arrows demand tighter precision at crown 34 ~34.8° with pavilion 40.6 ~ 40.9°. Even 1° off creates visible dullness or light leakage. Extremes over 36° crown or 41.5° pavilion cause performance issues.
Girdle: The Sturdy Band
The girdle is that narrow zigzag band around the diamond's widest point, protecting the stone during setting without adding unnecessary weight. It must be thick enough to prevent chips but not so thick it hides carat weight.
Aim for "thin to medium" or "medium to slightly thick." Faceted girdles are more refined than bruted styles. Extremely thin chips easily; very thick hides weight, makes diamonds look smaller, and creates dull bands.
Culet: The Invisible Dot
The culet is where pavilion facets meet at the bottom. Modern standards eliminate this entirely - facets now meet at a perfect single point with no visible dot through the table, maximizing pattern clarity and light return.
Choose "none" or "pointed" (both mean the same). Vintage stones often have small or medium culets. Medium or large culets show as black spots through the table, reducing brilliance.
Polish: Surface Perfection
Polish is the surface finish you see after faceting. Smooth, high-polish surfaces reflect light cleanly and sharply, and having no scratches, abrasions, burn marks, or polish lines.
For most diamonds, "Excellent" or "Very Good" grades ensures flawless, mirror-like surfaces. Very Good offers great value and is nearly indistinguishable. For premium Hearts-and-Arrows, insist on “Excellent”. "Fair" or "Poor" means visible scratches making diamonds look hazy and dull.
Symmetry: Flawless Harmony
Symmetry measures how precisely facets align. This includes facet shape consistency, equal sizes and angles, perfect outline, and centred culet. Perfect alignment directs light efficiently, creating balanced brilliance, fire, and scintillation without any dark zones.
Look for "Excellent" or "Very Good." Very Good is nearly indistinguishable from Excellent and offers better value. For Hearts-and-Arrows, Excellent is essential - only 1-2% of diamonds achieve this level. "Good" or lower means off-centre culets, unequal facets, and misalignments causing reduced sparkle.
Brilliant or Hall-of-Mirrors: Two Styles of Cutting Artistry
Diamonds fall mainly into two distinct cutting styles, each creating its own visual personality. Brilliant cuts are designed for maximum sparkle, while Step Cuts offer refined elegance through clean, architectural lines. Hybrid and vintage cuts bring their own character, blending tradition with contemporary brilliance.
Brilliant Cuts
Designed for maximum sparkle. Multiple triangular and kite-shaped facets reflect light from every angle, creating the lively fire and brilliance diamonds are famous for.
Round: Round Brilliant Cut is the most sparkling and the gold standard of diamond cutting. Featuring 57 precisely arranged facets (58 if the culet is defined as a facet), the round brilliant is the only shape with official cut grades. When cut to Triple Excellent, nothing outperforms it.
Fancy Cuts
Anything that isn't a round shape is a Fancy Cut. The below are modified adaptations of the round brilliant's faceting technique, cleverly redesigned for different diamond shapes.
Princess: Fancy Brilliant Cut with sharp-cornered square shape. It is modern, architectural, and brilliantly sparkly, beautifully complemented by protective prong settings.
Cushion: Fancy Brilliant Cut with pillow-shaped outline. Two completely different personalities exist. Modern cushion brilliant cuts scatter light into crushed-ice sparkle, while the Antique cushions flash with chunky facets and romantic fire.
Oval: Fancy Brilliant Cut with elongated proportions. The clever geometry means it appears larger than a round of the same carat, looks like a bigger diamond for your investment.
Pear: Fancy Brilliant Cut with teardrop silhouette. It blends the beauty of round and marquise cuts, appearing larger per carat while creating graceful, elongated elegance.
Marquise: Fancy Brilliant Cut with elongated marquise shape. Marquise diamonds has maximum finger coverage and vintage glamour.
Step Cuts
Step Cuts are faceted with long, rectangular facets that create a mesmerising hall-of-mirrors effect. Rather than scattering light into sparkle, they showcase clarity and transparency with quiet sophistication.
Emerald: Emerald Step Cut with large, open facets creates striking transparency. This cut celebrates purity and precision, making higher clarity grades truly shine, rewarding quality over size.
Asscher: Square Step Cut with deeper facets and dramatic cropped corners. Art Deco royalty in diamond form. The deeper cut creates mesmerising depth, peer into a well-cut Asscher and you'll see an infinite hall-of-mirrors pulling you in.
The Hybrid & Vintage Cuts
Radiant Cut: Hybrid Cut blending brilliant sparkle with step-cut elegance. It's the diplomatic answer when you can't choose between fire and sophistication, exceptionally versatile, wonderfully forgiving, and increasingly popular for good reason.
Rose Cut: Vintage Cut with flat-bottomed profile and domed top covered in triangular facets. Low-profile, bohemian, and beautifully romantic.
Old Mine & Old European: Vintage Brilliant Cuts hand-cut before modern technology. Larger facets and softer edges create gentle, candlelit sparkle rather than intense fire. Authentic period diamonds with timeless appeal.
