China's Ministry of Commerce announced in December new export restrictions targeting dual-use materials, including superhard materials to the United States, four months after Beijing placed restrictions on six-sided top presses, a key technology used in the manufacture of synthetic diamonds.

Industry experts believe that the latest round of export controls is expected to secure strategic resources and protect national security, so as to better safeguard China's place at the forefront of technological innovation.

"Implementing export controls on superhard material-related products is of great significance," said Sun Zhaoda, secretary-general of the superhard materials branch of the China Machine Tool & Tool Builders' Association.

Sun said superhard materials include synthetic diamonds, cubic boron nitride and composite materials made primarily from these two substances. The upstream of superhard materials includes raw materials, auxiliary materials and specialized equipment, like six-sided top presses.

"Export controls of superhard materials and related products are important to promoting the rational use of these products and technologies in various fields, especially in ensuring peaceful applications, which is in line with international practices," Sun said.

According to the association, China's industrial output of superhard materials has reached the highest level worldwide. The production of abrasive-grade synthetic diamonds has surpassed 20 billion carats, accounting for over 95 percent of the global market.

Along with that, nearly all of the specialized manufacturing equipment, such as six-sided top presses, is supplied by China. Sun said the country has become "the largest exporter of both upstream and downstream superhard materials".

"China's leadership in superhard materials is a result of its massive investment in research and development, as well as production," said Liu Jianguo, an expert in material sciences at Tsinghua University.

"This gives the country a competitive edge that many others cannot match. These materials are crucial for high-tech industries, and China's production could reshape global supply chains for the years to come," Liu said.

Alongside these export control measures, another notable development has been the dramatic price plunge in consumer-grade synthetic diamonds.

Since December, stocks related to consumer-grade synthetic diamonds have seen significant movement, with the price of a one-carat diamond of this category dropping to as low as 3,000 yuan — down 80 percent.

Simultaneously, global diamond giant De Beers, which has long been a dominant force in the sector, said in December that it decided to lower prices of its own products, signaling a broader trend in the diamond market.

The sudden drop in prices is a reflection of the industry's maturation as technology improves and production costs fall, especially from Chinese manufacturers, industry experts said.