Pink diamond returns to France a century after theft as natural diamond prices plummet

Nearly 100 years to the day after it was stolen, a priceless pink diamond has returned to public view in France. The display comes as natural diamond prices are at historic lows.

The nine-carat Grand Condé was unveiled at the Château de Chantilly, north of Paris, on October 17. But the broader market for mined diamonds tells a contrasting tale.

What Makes the Pink Diamond So Hard to Replace?

Rare pink diamond goes on display in France 100 years after amateur heist https://t.co/8dLTmSd0c3

— BBC News (World) (@BBCWorld) October 17, 2026

In October 1926, two amateur thieves broke into the château overnight. They concealed the pink diamond in a hollowed-out apple at their hotel.

About two months later, a hungry hotel maid bit into the apple and hit the diamond. Ever since, only a replica has been on display for visitors.

The pink color of the Grand Condé comes from intense pressure that warped its crystal structure deep underground. In contrast, yellow and blue diamonds get their color from nitrogen or boron traces. According to Sotheby’s, fewer than 0.15% of diamonds graded by the Gemological Institute of America (GIA) are predominantly pink.

But it is history, not just geology, that renders the Grand Condé priceless. The diamond has been part of the Condé collection since 1740 and made it through the French Revolution.

Why Are Ordinary Diamonds Worth Less Than Ever?

Most diamonds do not have such a pedigree, and their prices reflect that. An average 1-carat natural stone now costs $3,898, CNBC reported, a 51% decline from $8,007 in 2021.

The Diamond Standard Index, which follows investment-grade diamonds, reached a record low of 2,490 points in early August.

Polished diamond prices follow the same pattern. The IDEX Diamond Index, a key gauge for polished diamond values, has shed nearly half its worth since the start of 2022.

A previous oversupply of mined diamonds continues to pressure prices, even as miners now reduce production. At the same time, lab-grown stones cost up to 90% less yet are chemically identical.

Consequently, lab-grown diamonds appeared in 61% of engagement rings purchased in 2025. The disparity between diamonds and precious metals continues to grow, with gold having doubled since 2011.

The Grand Condé illustrates where value currently lies. Commodities are traded by weight, and gold itself faces a Bank of America prediction below $4,000 by year-end. Silver is trading close to its 2026 low.

In contrast, a pink diamond is valued for its rarity and provenance.

Similarly, rare Pokémon cards have outperformed Bitcoin and gold since 2021. If the supply of lab-grown diamonds continues to increase, provenance might become the sole premium for diamonds.