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Fine Jewellery

Investing in Diamonds: A Sober Assessment for High-Net-Worth Buyers

Feb 10, 2026·10 min read

By Thomas Lovaslokoy | NorwegianSpark SA

Diamonds occupy a curious space in the investment world. They are among the most concentrated stores of value by weight, universally recognised as symbols of wealth, and marketed relentlessly by an industry with extraordinary pricing power. Yet as investments, they have significant structural limitations that every prospective buyer must understand before committing capital.

This guide provides an honest assessment — the appeal, the drawbacks, and a clear-eyed view of whether diamonds belong in a serious portfolio.

The Uncomfortable Truth About Diamond Resale

The single most important fact about diamond investing is this: the moment you walk out of a retail jewellery store, your diamond is typically worth 20% to 50% less than what you paid. This is not a temporary market dislocation — it is a structural feature of the diamond market.

Retail markups cover the jeweller's overheads, branding, setting, and profit margins. When you attempt to resell, you are competing against wholesale supply. The secondary market is fragmented, illiquid, and opaque. There is no equivalent of a stock exchange for diamonds — no standardised pricing, no continuous market, and no obligation for anyone to buy your stone at a fair price.

This reality does not make diamonds worthless as an investment, but it means you must buy exceptionally well, hold for the long term, and accept that liquidity will always be limited compared to gold, equities, or even fine art.

Understanding the 4 Cs

Diamond valuation rests on four characteristics, universally known as the 4 Cs:

  • Carat weight: Larger stones are exponentially rarer, so prices increase non-linearly. A 2-carat stone is not merely twice the price of a 1-carat stone of equivalent quality — it can be 3-4 times the price.
  • Cut: The precision of the cutting determines brilliance and fire. Cut quality is graded from Excellent to Poor. For investment purposes, only Excellent or Very Good cuts should be considered.
  • Colour: Graded on a D (colourless) to Z (light yellow) scale. Investment-grade white diamonds are typically D, E, or F colour. Beyond G, resale becomes progressively more difficult.
  • Clarity: Ranges from Flawless (FL) to Included (I3). For investment, VS2 (Very Slightly Included) and above is the minimum threshold where stones retain their value profile.

For investment purposes, the sweet spot is typically 1 to 5 carats, D-F colour, VVS1-VS2 clarity, Excellent cut. These specifications represent the most liquid segment of the diamond market.

White Diamonds vs Fancy Coloured Diamonds

Fancy coloured diamonds — pinks, blues, yellows, and greens — have dramatically outperformed white diamonds as investments over the past two decades. The Argyle mine closure in 2020 permanently constrained pink diamond supply, driving prices for certified Argyle pinks up by an estimated 300-500% since 2015.

However, the coloured diamond market is even more illiquid and specialised than the white diamond market. Valuation requires deep expertise, the buyer pool is smaller, and price discovery is more difficult. Only investors with genuine knowledge or access to expert advisors should consider fancy colours.

Leibish specialises in natural fancy coloured diamonds and has one of the largest inventories of certified coloured stones available online. For those exploring the coloured diamond market, their platform offers an educational entry point with detailed grading information and pricing transparency.

GIA Certification: Non-Negotiable

Never purchase an investment-grade diamond without a certificate from the Gemological Institute of America (GIA). While other laboratories exist (AGS, HRD, IGI), GIA is the global standard, and its grading is the most conservative and consistent. A GIA certificate provides an independent, standardised assessment of all 4 Cs plus additional characteristics.

Importantly, two diamonds with identical GIA grades can still differ meaningfully in beauty and value. Fluorescence, for example, can reduce a diamond's market value by 5-15% even if it does not appear on the certificate as a negative factor. Always view stones in person or through high-resolution imaging before purchasing.

Lab-Grown Diamonds: Beautiful, But Not Investments

Lab-grown diamonds are chemically and optically identical to natural diamonds. They cost 60-85% less at retail. And they are terrible investments.

The reason is simple: supply is effectively unlimited. As production technology improves, lab-grown diamond prices will continue to fall — they already dropped roughly 30% in 2024-2025 alone. A natural diamond's value rests partly on geological scarcity. A lab-grown diamond has no such scarcity, and resale values reflect this: most jewellers will not buy back lab-grown stones at any meaningful price.

If you want a beautiful engagement ring at a fraction of the cost, lab-grown diamonds are excellent. If you want a store of value, they are not. Brilliant Earth offers both natural and lab-grown diamonds with strong ethical sourcing credentials — worth exploring for personal jewellery purchases where investment return is secondary to beauty and ethics.

Where to Buy Investment Diamonds

Avoid high-street retail jewellers for investment purchases. The markup structure makes it nearly impossible to achieve positive returns. Instead, consider:

  • Specialist diamond dealers: Firms that sell GIA-certified loose stones at near-wholesale prices.
  • Auction houses: Christie's, Sotheby's, and Bonhams regularly auction significant diamonds, particularly fancy colours. Buyer premiums (typically 20-26%) must be factored in.
  • Direct from diamond centres: Antwerp, Tel Aviv, and Mumbai are global diamond trading hubs where professionals buy and sell.

Storage and Insurance

Diamonds must be insured at replacement value and stored securely — either in a home safe (rated to an appropriate insurance standard) or a bank safety deposit box. Annual insurance premiums typically run 1-2% of appraised value. Reappraisal every 2-3 years is advisable, as market values fluctuate.

Better Alternatives for Most Investors

For the vast majority of high-net-worth investors, there are more liquid, transparent, and cost-efficient alternatives to diamond investing. Physical gold offers genuine inflation protection with deep global liquidity. Fine wine has delivered competitive returns with growing market infrastructure. Even art now benefits from fractionalised ownership platforms that improve liquidity.

Diamonds can work as a small, highly concentrated component of a diversified alternative allocation — particularly natural fancy colours purchased at wholesale or auction pricing. But they should never constitute a significant percentage of investable wealth. Explore our partner directory for a broader range of alternative investment platforms and providers.