Editor’s Note
The recent Louvre theft has unexpectedly fueled a debate on diamond valuation. As prices for natural diamonds decline, the rise of lab-grown alternatives—significantly driven by Chinese production—challenges traditional notions of value and permanence. This article explores the shifting dynamics behind the glitter.
The recent theft of treasures from the Louvre sparked a global discussion on diamond prices. This round of price comparisons revealed that diamond prices have fallen by about 30% over the past two years. The advertising slogan says “A diamond is forever,” so why are prices falling instead of rising?
Industry analysis suggests the price drop is related to lab-grown diamond technology, and interestingly, China plays a significant role in this. Some netizens even say discussing diamonds must consider the development of chips and artificial intelligence. Is this an exaggeration?
Recently, a company in Henan announced the cultivation of a 156.47-carat diamond rough, certified by the International Gemological Institute (IGI) as the world’s largest known single-crystal lab-grown diamond. This sparked widespread online discussion.
Some netizens claim 99% of ordinary people cannot distinguish between natural and lab-grown diamonds. Others believe natural diamonds are inherently better but can’t specify why. Some even confuse them with cubic zirconia.
It’s important to clarify: cubic zirconia is not a diamond. Lab-grown diamonds, also known as cultured or synthetic diamonds, are real diamonds. To understand this better, we visited the High-Pressure Physics Research Institute at Ningbo University.
First, both natural and lab-grown diamonds are crystalline forms of pure carbon (C), making them the same substance chemically. So, what’s the difference?
Ma Shuailing, Associate Researcher at Ningbo University’s School of Physical Science and Technology, explained this. The high price of natural diamonds stems from their scarcity, closely tied to their natural formation process.
Diamond, known as ‘diamond’ in mineralogy, has been found in over 30 countries. Typically, 23 tons of ore yield only about 4.5 carats of diamonds, with merely 0.45 carats suitable for jewelry after processing.
Scarcity makes natural diamonds expensive, with prices reaching tens of thousands of RMB per carat. They have become synonymous with love, not just for their rarity and cost, but for their perceived indestructibility and brilliance.
Lab-grown diamonds share these exact properties but have a drastically different formation timeline. How is this achieved?
Lab-grown diamonds are primarily produced via two methods: High-Pressure High-Temperature (HPHT) and Chemical Vapor Deposition (CVD). Ningbo University’s ultra-high temperature and pressure lab uses the HPHT method, simulating the extreme conditions of Earth’s interior.
Diamonds were first grown in labs in the mid-1950s, but they were too small for jewelry. Production of larger, gem-quality crystals began in the mid-1990s and continues today, with more companies entering the market.
Lab-grown diamonds are made from simple materials in a short time, making them much more affordable. Prices are in the thousands of RMB per carat, about one-tenth the cost of natural diamonds, while their properties are identical. This explains the sustained price drop of natural diamonds.
In early 2025, The Guardian reported that natural diamond prices in stores had fallen 26% compared to two years prior. De Beers, the world’s largest diamond company, failed to sell its 2024 inventory by year-end and had to cut mine production by 20%.
The Guardian attributed the price drop to decreased demand in China, a sluggish global economy, and fewer marriages. However, the biggest change was the emergence of lab-grown diamonds, which now hold a 45% share of the bridal market. The analysis also noted that while natural diamond prices fell due to lab-grown competition, lab-grown diamond prices plummeted even more sharply, down 74% from 2020 to early 2025, primarily due to technological advancements and economies of scale.
Almost all analyses on lab-grown diamond technology and scale mention China. A 2025 diamond industry report stated that due to continuous technological innovation, China’s lab-grown diamond market has gained significant global importance. Expertise in HPHT technology, combined with the growing popularity of CVD, allows China to produce high-quality synthetic diamonds at competitive prices for both industrial and jewelry sectors. This efficiency enables Chinese manufacturers to produce lab-grown diamonds at costs 20% to 40% lower than in Western countries.
This introduces the concept of “industrial demand” for diamonds. If we only think of diamonds in terms of jewelry and love, we’re missing the bigger picture. Diamonds are indispensable in industry, military, and even artificial intelligence. If their use were limited to jewelry, scientists wouldn’t be so dedicated to R&D in this field.
Discussing other uses brings us back to diamond’s physical properties. Firstly, diamond is one of the hardest known materials. High-end manufacturing uses super-hard diamond to process precision components.
Wang Xuguang, AI expert and doctoral supervisor at the Chinese Academy of Sciences, explained this. China’s leading position in lab-grown diamonds is partly driven by industrial applications, born out of necessity.
China has very few natural diamond deposits, with small, low-quality mines in places like Shandong and Liaoning. Importing industrial abrasives or natural diamonds was difficult, so domestic R&D and production became essential. In 1963, China successfully cultivated its first synthetic diamond, becoming the fifth country in the world to do so.
Mass-producing industrial diamonds requires thousands of presses, a dense network of coating, bonding, and grading facilities, and, crucially, decades of accumulated process technology—expertise now largely concentrated in China. By 2022, China’s diamond output exceeded 16 billion carats, accounting for over 90% of global production.
According to the U.S. Geological Survey, about 77% of the U.S. industrial diamond supply comes from China, with 8% from South Korea and 5% from the UK.
On October 9, 2025, an announcement from China’s Ministry of Commerce and General Administration of Customs drew widespread attention. Announcement No. 55 of 2025 imposed export controls on items related to ultra-hard materials, including specific lab-grown diamond products and related manufacturing equipment, effective November 8.
Many might ask: Why does the chip industry need diamond? Beyond hardness, it’s also related to diamond’s exceptional thermal conductivity.
Thermal conductivity measures a material’s ability to transfer heat, measured in watts per meter-kelvin (W/m•K). The top ten natural thermal conductors are: diamond, silver, copper, gold, aluminum nitride, silicon carbide, aluminum, tungsten, graphite, and zinc. In terms of specific values, diamond is in a league of its own, far ahead of the others.
Looking to the future, one of the fundamental challenges in chip manufacturing is temperature control. For most silicon-based chips, excessive heat makes them unreliable. Diamond is a perfect “heat sink,” effectively dissipating heat generated by semiconductor devices.
Diamond has already become an indispensable component in chip manufacturing. Beyond AI, it’s also a crucial defense material; its hardness and thermal conductivity make it valuable for manufacturing munitions and cooling high-power radar and laser systems.
Now, unlocking diamond’s vast potential and gaining an edge in R&D has become the next goal for researchers.
Producer: Liang Yin
Director: Zhang Heng
Editor: Yu Erya