How to choose a natural diamond
Most people want the best-looking diamond for their budget.
By the CTJ Jewellery team, led by founder Greg Ward · Updated September 2026 · Editorial policy
Key facts
- Cut has the biggest effect on appearance
- Eye-clean clarity is the practical target
- Match colour to the metal
- Just under a round weight looks the same, for less
- Shape changes how large a diamond looks
- Always compare diamonds in person
Which of the four Cs matters most?
Cut. A well-cut natural diamond can look brighter than one of higher colour or clarity.
| Grade | What to look for |
|---|---|
| Cut | Excellent |
| Colour | Suited to the metal: whiter for platinum and white gold, warmer grades work in yellow and rose gold |
| Clarity | Eye-clean, checked in person |
| Carat | The size that suits the hand and the budget |
Which shape should you choose?
Round brilliant returns the most light. Oval, pear and marquise look larger for their weight. Emerald and asscher step cuts show clarity, so choose them carefully.
Diamond shapesHow do you get the most from your budget?
Buy just under a round weight, such as 0.95ct instead of 1.00ct. Choose an eye-clean clarity rather than paying for flawless. In yellow gold, a warmer colour grade can look white.
What moves natural diamond pricesWhy compare natural diamonds in person?
Two diamonds with the same grades can look very different in real life. Seeing them side by side shows differences in brilliance and how inclusions sit that a report can’t.