Understanding the 4 Cs (and Why They’re Not the Whole Story)
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Understanding the 4 Cs (and Why They’re Not the Whole Story)
When shopping for a diamond, you'll almost always hear about the 4 Cs: cut, clarity, colour, and carat weight. These are the traditional grading factors established by the Gemological Institute of America (GIA), and they’re a useful starting point — but they’re far from the whole story.
At Auclair, we believe in informed decisions. That means helping you understand the nuances that make one diamond feel more special than another, even when they share the same grade on paper.
Cut
Often misunderstood, the cut isn’t about the shape (round, oval, etc.) — it’s about how well the diamond reflects light. A well-cut diamond will have superior sparkle, brilliance, and fire. We prioritise excellent and very good cuts for this reason: it’s the single biggest factor in how beautiful a diamond looks.
Clarity
Clarity refers to the internal and external characteristics (inclusions and blemishes) within a stone. While it might be tempting to seek the highest clarity, many inclusions are microscopic and invisible to the naked eye. That’s why we recommend prioritising eye-clean stones over flawless ones — it’s a smarter way to allocate your budget.
Colour
Diamond colour is graded on a scale from D (colourless) to Z (light yellow or brown). Most customers can’t tell the difference between a D and an F in real life. That’s why we help you find the sweet spot — stones that look bright and white without the premium pricing.
Carat
Carat refers to the weight of the diamond, not the size — though heavier stones are often larger in appearance. But proportions matter. A well-cut 1.0ct diamond can look bigger (and brighter) than a poorly cut 1.2ct stone. Bigger isn’t always better.
But There’s More: What the 4 Cs Don’t Tell You
Fluorescence
Some diamonds emit a soft glow under UV light. This is called fluorescence. In most cases, it has no negative effect — and can even make lower-colour diamonds appear whiter. But in rare cases, strong fluorescence can make a diamond look cloudy. We’ll always let you know if it’s a factor worth considering.
Symmetry & Polish
These two aspects affect how well the diamond has been cut and finished. Excellent symmetry and polish contribute to better light performance and a more refined overall look — even if they don’t show up as big-ticket grading terms.
Shape & Spread
A diamond’s shape affects its personality and perceived size. Some shapes (like oval or marquise) give more surface area for the same carat weight, offering a larger look for less. We guide you through these trade-offs so you can find a stone that suits your style and budget.
Final Thoughts
The 4 Cs offer a solid foundation, but they’re only part of the picture. At Auclair, we help you go beyond the grading report — to find a diamond that sparkles in person, not just on paper. Because the best diamonds aren’t just well-rated. They’re well-chosen.