Diamonds · 5 min read
Fancy Colored Diamonds: Nature's Rarest Gems
Why pink, green and blue diamonds command record prices, how their colour forms, and what to check before you invest.
How fancy colour happens
Less than one in ten thousand diamonds has a natural fancy colour. Each hue has a different origin: pinks and reds from distortions in the crystal lattice, greens from natural radiation, blues from trace boron, and yellows from nitrogen. Because the cause is geological accident, supply can never be increased — which is why fancy colours have outperformed almost every other gem category at auction.
Reading a fancy colour grade
Laboratories grade fancy colours on three axes: hue (the dominant colour), tone (lightness to darkness) and saturation (strength). The grades you'll see on a report run from Faint through Fancy Light, Fancy, Fancy Intense and Fancy Vivid. Saturation drives price: a Fancy Vivid can be worth many times a Fancy Light of the same size.
Natural versus treated
Colour can also be induced artificially by irradiation or high-pressure, high-temperature treatment. Treated stones are beautiful but worth a fraction of natural-colour equivalents, so the laboratory report must state the colour origin explicitly. Every fancy coloured diamond at Riakoob is natural in colour and accompanied by a report saying so.
Buying with confidence
Insist on a report from a recognised independent laboratory, examine the stone in person or under controlled lighting, and buy from a seller who insures the stone and stands behind its value. Our 12-month value promise applies to every fancy coloured diamond we sell: if the insured value is not retained, we refund your money.
Further reading & references
Ready to collect?
Every Riakoob piece arrives certified, insured and covered by our 12-month value promise.
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