A guide to brilliance, proportion, and optical magic
A diamond’s sparkle doesn’t depend solely on its weight or clarity. The most important factor — the one that brings a stone to life — is its cut. It’s the cut that determines how light enters the stone, reflects internally, and returns to the eye as brilliance and fire.
In this article, we explore:
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what cut really means,
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which shapes reflect light best,
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how to choose a cut that suits the wearer,
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and what role proportion plays in creating maximum brilliance.
What is a diamond cut?
Cut is not just the shape of the stone — it’s the art and science of transforming rough diamond into a gemstone with perfect optical symmetry.
A well-cut diamond:
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maximizes sparkle and light return,
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minimizes visible flaws,
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can appear larger than its carat weight,
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and enhances the colour and clarity of the stone.
The most brilliant cut: round brilliant
The round brilliant cut is by far the most popular — and for good reason. It was developed using precise mathematical models to maximize light performance.
With 57 or 58 facets, it creates the ultimate balance between brilliance, fire, and scintillation:
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Brilliance – bright white light reflections.
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Fire – flashes of rainbow colours.
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Scintillation – sparkle that moves with the diamond.
If you want the most dazzling effect, this cut outshines them all.
Other cuts — how do they compare?
Princess (square)
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Modern and geometric.
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Second-brightest cut after round brilliant.
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Pointed corners require protective setting.
Oval
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Elegant and elongating.
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Similar sparkle to round, but softer in character.
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May show a slight “bow-tie” shadow in the centre.
Cushion
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Vintage-inspired, rounded square.
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Romantic and soft with a classic feel.
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Looks stunning in halo settings.
Emerald (step-cut rectangle)
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Less sparkle, more transparency and elegance.
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Highlights the clarity and structure of the stone.
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Best with high-clarity diamonds.
Marquise, pear, heart, radiant…
Each has its own geometry, brilliance, and personality. Choose based on style, hand shape, and personal expression.
Proportions matter more than shape
Not all diamonds with the same cut sparkle equally. Why?
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Too deep: light escapes through the bottom — less brilliance.
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Too shallow: light leaks from the sides — dull appearance.
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Ideal cut: light returns perfectly to the eye.
That’s why you should always look for diamonds graded “Excellent” or “Very Good” for cut quality in trusted certifications like GIA. You’ll see the difference instantly.
Choosing a cut for her
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Romantic and soft personality? Consider cushion, oval, or pear.
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Contemporary or bold style? Try princess, radiant, or asscher.
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Classic and minimalist? Round brilliant or emerald.
There’s no wrong choice — only the right one for the person who’ll wear it.
Final thoughts
A diamond’s sparkle isn’t just a gift from nature — it’s a masterpiece of craftsmanship. A well-cut stone can outshine a larger, poorly cut one.
If you want to see the difference firsthand, visit us at Inkluz, Mokotowska 64, Warsaw — where true brilliance begins with expertise.