What determines diamond price?
Diamond prices are primarily determined by the 4Cs — but not in equal measure. Cut has an outsized impact on visual quality. Carat drives base price exponentially (not linearly). Colour and clarity grades near the top of their scales command steep premiums for differences invisible to most eyes.
Beyond the 4Cs, market forces, certificate prestige, fluorescence, and shape also move the price.
Why prices aren't linear with carat
A 2-carat diamond does not cost twice as much as a 1-carat diamond of the same quality — it typically costs three to five times as much. This is because large rough diamond crystals are far rarer than smaller ones. Every increase in carat weight narrows the pool of available stones significantly.
This non-linearity is why buying just below round numbers (0.95ct, 1.90ct, 2.90ct) can deliver meaningful savings with no visible size difference.
Natural diamonds and long-term value
Well-graded natural diamonds (GIA or IGI certified, Excellent cut, G-H colour, VS1-VS2 clarity, 1ct or above) have historically retained value reasonably well. They are not investments in the financial sense — the retail-to-resale spread is typically 20–40% — but they do not depreciate to zero.
Larger, higher-quality stones (2ct+, D-F colour, VVS clarity) retain value best. Smaller, lower-grade stones have thin resale markets.
Lab-grown diamonds and value
Lab-grown diamond prices have fallen significantly as production scales. A lab-grown diamond purchased today may be worth considerably less in five to ten years as supply continues to grow.
If you view a diamond as jewellery rather than as a store of value, this is not a concern — the piece retains its beauty regardless of resale price. If long-term value retention matters, natural is the more conservative choice.
Buy-back and resale
SAAT's buy-back guarantee offers 70% of original purchase price within 5 years for natural diamonds meeting our quality criteria. This provides a meaningful floor if your circumstances change.
For private resale, certified diamonds (especially GIA-certified naturals) sell most easily. The certificate is the buyer's assurance — without it, resale is difficult.
The right way to think about it
A fine diamond is not primarily a financial investment — it's a marker of a meaningful moment, an object of daily beauty, and a potential heirloom. Its value is partly monetary and partly personal.
Buy the diamond that moves you, treat it well, and the financial considerations will largely take care of themselves over a long enough time horizon.