1-carat RAPI down 0.9%, with smaller sizes falling sharply.

Diamond prices declined in many categories during September. The US tariffs and the sale of De Beers perpetuated uncertainty in the market.

Prices declined sharply for round polished goods under 1 carat and were mixed for larger sizes, reflecting a split that has been evident for several months. Long fancy shapes were hot, particularly in 2 carats and up.

The RapNet Diamond Index (RAPI™) for 1-carat goods — which tracks round, D to H, IF to VS2 diamonds — fell 0.9% in September. Both the 0.30- and the 0.50-carat indices fell 6%. RAPI for 3 carats was flat.

SI-clarity diamonds saw a more negative 1-carat trend than the RAPI qualities did. Prices of round, D to H, SI diamonds in that size dropped 2% in September, according to RapNet data. Prices fell 3.8% for 0.30-carat goods in those categories, and 3.9% for 0.50 carats.

Trading at Hong Kong’s Jewellery & Gem World show mirrored the bifurcation between larger and smaller diamonds: There was mostly demand for the former, especially long fancies.

Independent US jewelers enjoyed steady retail business ahead of the holiday season. However, the import duties restricted overseas suppliers’ sales to the important American retail market.

The European Union obtained a zero-tariff deal for all diamonds polished in the bloc. Botswana is negotiating a similar arrangement. The tariff causing the most concern is the 50% rate on Indian goods. On September 5, the White House added diamonds to a list of possible exemptions for countries that reached trade agreements with the US.

Indian manufacturers have reduced polished production amid weak demand. The country’s rough imports fell to $768.7 million in August from $1.15 billion in July, though the figure was 14% higher than in August 2024.

Anglo American’s sale of De Beers was still in progress at press time. The Botswana government expressed interest in a majority stake, while Angola bid for a minority holding. De Beers extended its sightholder contract through June 2026 amid the uncertainty.

About the RapNet Diamond Index (RAPI™): The RAPI is the average asking price, in hundred dollars per carat, of the 10% lowest-priced round diamonds in each of the top 25 quality categories (D-H, IF-VS2, GIA-graded, RapSpec-A3 and better) offered for sale on RapNet® (www.rapnet.com). Additional information is available at www.rapaport.com.

About the Rapaport Group: The Rapaport Group is an international network of companies providing added-value services that support the development of ethical, transparent, competitive and efficient diamond and jewelry markets. Established in 1978, the group has more than 20,000 clients in over 120 countries. Group activities include Rapaport Information Services, providing the Rapaport benchmark Price List for diamonds, as well as research, analysis and news; RapNet, the world’s largest diamond trading network, with daily listings of 1.5 million diamonds valued at more than $7.2 billion; and Rapaport Trading and Auction Services, the world’s largest recycler of diamonds. Additional information is available at www.rapaport.com.

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