Diamond Cut Guide
Where Sparkle Meets Precision
Diamond cut is the most critical of the 4Cs it determines how brilliantly a diamond reflects light. A well-cut diamond will shimmer with fire, brilliance, and scintillation, even if it has average clarity or colour.
More than just shape, cut refers to how well the diamond's facets interact with light. It’s all about proportion, symmetry, and polish and it’s what makes a diamond truly come to life.
Cut Grades Explained
Cut grades apply mainly to round brilliant diamonds, as this shape is most precisely evaluated. The most widely used grading scale is:
| Grade | Description |
|---|---|
| Excellent | Maximum fire, brilliance, and sparkle |
| Very Good | Exceptional sparkle with slight differences in proportions |
| Good | Still attractive, but may lack some light performance |
| Fair | Noticeable dullness or less efficient light return |
| Poor | Lacks sparkle; light escapes through the bottom/sides |
💡 The Real Gem Tip: Always prioritise Excellent or Very Good cut for the best sparkle, especially in engagement rings.
The 3 Elements of Diamond Sparkle
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Brilliance: White light reflected from the diamond
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Fire: The rainbow dispersion of light
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Scintillation: The sparkle as the diamond moves
A well-cut diamond balances all three, creating that irresistible shimmer.
Why Cut Impacts Beauty Most
Even a high-carat, flawless diamond can appear dull with a poor cut. Conversely, a smaller diamond with an excellent cut will often appear larger and more brilliant.
Cut is the only one of the 4Cs influenced entirely by human craftsmanship. That’s why we work only with trusted cutters who follow ideal proportions.
Our Standards at The Real Gem
At The Real Gem, we only use diamonds with Excellent or Very Good cut grades across our collections. Every stone is hand-inspected to ensure:
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Perfectly symmetrical facets
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Strong light return and proportion
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Flawless polish to maximise fire
We believe sparkle is non-negotiable.
Cut and Price
Cut significantly affects price, but it’s worth the investment. A diamond with excellent cut can outshine more expensive stones with higher colour or clarity.
💡 When in doubt, spend more on cut than other Cs — it’s what your eyes will notice most.