Diamonds: buying guide
How to judge a diamond on the 4Cs, read a grading report, choose a shape and understand natural versus lab-grown resale value.
Quick answer
A diamond's value is set by the 4Cs — carat, cut, colour and clarity — plus whether it is natural or lab-grown. A GIA, IGI or AnchorCert report states these grades independently. In the UK, natural diamonds resell far better than lab-grown stones of the same size.
The 4Cs explained
Carat, cut, colour and clarity — what each grade means and where the best value sits.
1ct natural G/VS2 excellent cut: roughly £3,500–£6,500 second-hand
Diamond shapes and cuts
Round brilliant, oval, emerald, cushion, princess, pear, marquise, radiant and asscher compared.
Fancy shapes typically 20–40% cheaper than rounds of equal grade
Lab-grown vs natural diamonds
Identical chemistry, very different resale. What sellers and buyers need to know.
1ct lab-grown: often £300–£1,000 second-hand; natural equivalent several times more
Diamond grading reports
GIA, IGI, AGS, HRD and AnchorCert reports — how to read and verify them.
A trusted report can add 10–30% to resale value
Buying or selling a diamond?
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