Zhecheng, Henan: Inside a China Lab-Grown Diamond Production Hub

Around 1983, an engineer named Feng Jinzhang opened a small synthetic diamond factory in Zhecheng, a farming county in eastern Henan. By the end of the decade, according to a 2024 Sixth Tone report, the county was full of diamond processing businesses, many started by people who had learned the trade in the first ones. Four decades later, Chinese media call Zhecheng the “Diamond Capital of China”, and a local company reported growing a 156.47 ct rough crystal in 2025.

Zhecheng is a county of a little over 600,000 people under Shangqiu city in Henan province. Its industry grew from industrial diamond into a cluster of companies that build and run HPHT presses, grow rough, sort, cut and trade. Henan as a whole is widely reported to produce most of China’s lab-grown diamonds, and China about half of the world’s. For a buyer, a hub like this means deep supply and specialist skills in one place, but each supplier there still has to be checked on its own.

Zhecheng at a glance

How the industry grew

China made its first synthetic diamonds in the 1960s. Sixth Tone dates the first to Beijing in 1963; other Chinese accounts credit Henan with the first six-anvil press diamond in 1965. Henan became a center of the ultra-hard materials industry, first for abrasives and cutting tools. Zhecheng’s first factory followed in the early 1980s, and over the next decades the county moved from industrial grit to gem-quality crystals as HPHT presses grew larger and growth control improved.

How big is it?

Figures vary and are hard to check. Local officials quoted by Sixth Tone say China makes about half of the world’s lab-grown diamonds and Henan about 80% of China’s, while the article itself notes that reliable statistics are hard to find. A 2025 Our China Story report puts Zhecheng at about 60% of China’s output and forecasts around 12 million carats for 2025. Industry data reported by IDEX in 2025 also puts China at about half of world production, mostly by HPHT. Treat the county and province figures as reported estimates, not audited statistics.

Why HPHT dominates in Henan

The region’s industrial diamond heritage built decades of experience with cubic presses, the core of HPHT growth, and with the graphite, catalyst metals and parts they use. HPHT is efficient for melee and small stones and is now also used for large colorless crystals; GIA notes that colorless HPHT stones of over 10 ct have been produced. Sixth Tone reports that Indian producers lean toward CVD instead, which is why buyers often compare the two regions by method as much as by price.

The industry chain around Zhecheng

1. EquipmentCubic presses, parts, maintenance
2. MaterialsGraphite, metal catalysts, seeds
3. GrowthHPHT growth of rough
4. ProcessingSorting rough, cutting, polishing
5. TradingRough and polished sales, export
6. ServicesLogistics, grading submissions, online sales

Not every company covers every link, and many specialize in one or two. Some focus on industrial products and only trade gem goods, so ask what share of a supplier’s business is gem-quality, and which steps for your order happen at its own site.

What a hub means for buyers

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To check a supplier in the region, confirm its registration and address, ask which steps it performs itself, verify report numbers with the laboratory, order a sample that copies your volume order, and get growth method and treatment status in writing. See how to evaluate a supplier in China.

Visiting the area

Zhecheng is in Shangqiu, in eastern Henan. Shangqiu is on China’s high-speed rail network, and Zhengzhou, the provincial capital, has an international airport. Visits are arranged with individual suppliers in advance. Bring your specifications and reference samples, so the visit can include a review of actual stones, and ask:

1. Which steps happen at this site?
2. How are stones sorted and checked before shipment?
3. Which laboratories do you use for reports?
4. How do you record growth method and treatment?
5. Can we see stones that match our specification?

Zhecheng questions

Written bySiyu Wang

Lab-Grown Diamond Production Manager, NUVU

9+ years optimizing HPHT & CVD growth recipes and overseeing large-scale lab-grown diamond manufacturing.

Credentials: IGI Laboratory Grown Diamond Specialist

About NUVU. NUVU is the international brand of New Perspective Superhard Materials Co., Ltd. in Zhecheng, Henan, China. We grow HPHT lab-grown diamonds in-house and cut, polish and match stones in our own workshop.