The nine-carat Grand Conde diamond returned to public display at the Chateau de Chantilly in France on October 17. The stone was stolen in October 1926 by two thieves and recovered two months later after being hidden inside an apple. It has been part of the Conde collection since 1740.
While the rare pink diamond remains highly valued due to its history and rarity, the broader natural diamond market is experiencing a significant downturn. According to CNBC, the price of an average one-carat natural diamond has fallen to $3,898, representing a 51% decline from its 2021 price of $8,007.
Market benchmarks reflect this downward trend. The Diamond Standard Index reached a record low of 2,490 points in early August, while the IDEX Diamond Index has lost nearly half its value since early 2022. Excess supply of mined stones continues to pressure prices despite production cuts by miners.
Lab-grown diamonds are increasingly impacting the market, as they are chemically identical to natural stones but cost up to 90% less. In 2025, lab-grown diamonds were used in 61% of engagement rings sold. Analysts suggest that for natural diamonds, provenance may become the primary factor sustaining value as supply of synthetic alternatives grows.
