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China Lab-Grown Diamond & CVD Diamond Industry Map: Which Companies, Where They Are, and What They Actually Make (2026 Edition)

A verifiable roster of China's synthetic diamond and lab-grown diamond industry: who runs HPHT, who runs MPCVD, which companies build MPCVD reactors, where each sits in the diamond chain, and which category of supplier fits which sourcing need. Every industry statistic is attributed and its denominator stated — China produced roughly 22 million carats of lab-grown diamond in 2024, about 63% of global output (People's Daily Online, citing the 2024 report on China's jewellery industry); China accounts for over 90% of global diamond output and Henan for over 80% of national capacity (Huifeng Diamond 2025 annual report); Henan accounts for over 80% of national synthetic diamond output (North Industries Group Red Arrow (China North Industries Group / NORINCO) 2025 annual report). This map deliberately carries no revenue, profit or other financial figures for any company — those change every quarter and go stale fast, so consult each company's latest periodic report directly. What this article does is establish who exists, where they are, what they make, and where the evidence is. It is a map, not a ranking, and it passes no judgement on any company.

China Lab Grown Diamond ManufacturersPublished 2026-07 · Updated 2026-07-26 · 14 min

01Start with the denominators: the 'share of world' numbers are not one number

Ask how much of the world's synthetic diamond China makes and the public record hands you several different numbers with several different denominators. First, lab-grown diamond output: People's Daily Online (30 September 2025), citing the 2024 report on the development of China's jewellery industry, puts 2024 Chinese lab-grown diamond production at about 22 million carats — up 144.44% year on year from 2023, as that report frames it — and equal to 63% of global output. Second, all synthetic diamond including industrial abrasive grit: Huifeng Diamond's 2025 annual report states that China is the world's largest diamond producer with over 90% of global output, and that Henan holds over 80% of national capacity — note that the first half of that sentence is measured in output and the second half in capacity, which are not the same denominator. Third, intra-China concentration measured in output: Red Arrow's 2025 annual report states that Henan accounts for over 80% of national synthetic diamond output, over 95% of national cubic boron nitride output, and 80% of national lab-grown diamond output. And there is a fourth figure that neatly demonstrates the inconsistency even among listed filers: Liliang Diamond's 2025 annual report describes China as holding 50% of world lab-grown diamond output — the same denominator as the 63% figure above, thirteen percentage points apart. The conclusion is blunt: treating 63%, 90%, 80% and 50% as interchangeable is the most common error in secondary coverage, and any one of them must be quoted with its source and its year. The People's Daily piece also records a structural judgement, attributed to Li Jianhua, CTO of the diamond division at Henan Huanghe Whirlwind: China is strong upstream in growth capacity and comparatively weak midstream in cutting and polishing.

02The four Henan cities: Nanyang, Zhengzhou, Changge (Xuchang), Zhecheng (Shangqiu)

Red Arrow's 2025 annual report describes the Henan cluster in plain terms: a diamond industry cluster spanning R&D, production and sales, centred on leading enterprises in Nanyang, Zhengzhou, Xuchang and Shangqiu. Each of those four maps onto identifiable companies. Nanyang is the home of Zhongnan Diamond Co., Ltd.; Red Arrow's stated office address is inside the Zhongnan Diamond compound at 1669 Zhongjing North Road, Nanyang. Note that the listed entity's registered address only moved from Xiangtan, Hunan (1 Rhine Road, German Industrial Park, Xiangtan National Hi-Tech Zone) to 569 Liangxiang Road, Nanyang, Henan on 13 March 2026 — which is why Hunan has historically appeared in geographic breakdowns of Chinese synthetic-diamond listed companies. Zhengzhou is the research origin of the abrasives industry: Sinomach Precision's 2025 annual report records that the Third Abrasives Research Institute, held through its superhard materials vehicle Sinomach Diamond, was founded in 1958 and synthesised China's first synthetic diamond in 1963 and its first cubic boron nitride in 1966; the same report calls it the only comprehensive research institute in China's abrasives industry (that 'only' is the company's own statement in its annual report and is not third-party verified). Sifangda is also in Zhengzhou — its 2025 annual report gives both registered and office address as 109 Tenth Street, Zhengzhou Area (Jingkai) of the Henan Pilot Free Trade Zone — and its CVD business sits in majority-held subsidiary Henan Tianxuan Semiconductor. The Zhengzhou Airport Economy Zone is additionally building the Zhengzhou lab-grown diamond international trading centre (People's Daily Online, 30 September 2025). Changge, Xuchang is home to Henan Huanghe Whirlwind, whose 2025 annual report summary gives a contact address of 200 Renmin Road, Changge. In Zhecheng, Shangqiu, Liliang Diamond's 2025 annual report gives both registered and office address as Zhecheng County Industrial Cluster Zone (postcode 476200); Huifeng Diamond's 2025 annual report gives an office address of 10 Beihai Road, Zhecheng County Industrial Cluster Zone (that report has no separate registered-address field, and the company domicile stated in its financial-statement notes is 'Zhecheng County Industrial Cluster Zone, Beihai Road' with no street number — we do not back-fill the office address's street number into the domicile). Both sit inside the same county-level cluster. There is an earlier independent data point on Zhecheng's scale: Beijing Review reported on 29 September 2022 that of 9 million carats of global lab-grown diamond output in 2021, 4 million carats came from Zhecheng County, Henan — the origin of the county's 'diamond capital' label.

03Beyond Henan: what Changsha (Hunan) and Xi'an (Shaanxi) actually do

Changsha's position on this map is not crystal growth but diamond consumables. Dialine New Materials (300700.SZ) states on its own 'About' page (accessed 26 July 2026; company websites can be rewritten at any time and are not archived, hence the access date) that it was founded in 2009, listed on the ChiNext board of the Shenzhen Stock Exchange in September 2017, employs over 1,000 people, and serves photovoltaics, consumer electronics, hydrogen and energy storage, semiconductors and AI, with products including tungsten-core diamond wire, tungsten wire rope, ultra-high-purity quartz sand and graphite composite bipolar plates; its industrial park in Yuelu District, Changsha came online in 2016. The same site describes Dialine as the first company in China to industrialise diamond wire and as the first listed Chinese company to break foreign technology monopoly and mass-produce diamond wire — both 'first' claims are Dialine's own statements on its own website (accessed 26 July 2026) and are not third-party verified. In other words Changsha supplies the wire that cuts hard and brittle materials, not lab-grown rough. Separately, as noted above, Red Arrow's listed entity was registered in Xiangtan, Hunan until March 2026. Xi'an, Shaanxi concentrates on two things: MPCVD reactors and diamond semiconductor substrates. Securities Times reported on 9 January 2024 that Professor Wang Hongxing's team at Xi'an Jiaotong University had achieved batch production of 2-inch heteroepitaxial single-crystal diamond free-standing substrates using in-house MPCVD technology, and can supply 1–2 inch large-area high-quality single-crystal diamond substrates, having completed principle innovation, lab trials and pilot production. On the equipment side, the CMPE trade round-up of MPCVD systems and domestic players (27 March 2026) lists two Xi'an companies: Xi'an Demengte Semiconductor Technology and Xi'an ENTASK Semiconductor Technology.

04The two process routes: how they differ, and what that decides

For process parameters the baseline is GIA's own explainer (Dr. James E. Shigley, HPHT and CVD Diamond Growth Processes, 25 July 2016). In HPHT, a seed is placed in a purpose-built press, the growth chamber is heated to 1300–1600°C at pressures above 870,000 psi, a carbon source such as graphite dissolves in a molten metal flux of iron, nickel or cobalt, and carbon migrates down the temperature gradient to crystallise on the cooler seed over several days to weeks. In CVD, a vacuum chamber is filled with hydrogen plus a carbon-bearing gas such as methane, heated to roughly 900–1200°C, and a microwave beam breaks down the gas into a plasma from which carbon diffuses onto cooler flat diamond seed plates; the full growth run can take three to four weeks and crystals are removed every few days so that non-diamond carbon can be polished off the top surface before growth resumes, so a batch typically involves several stop/start cycles. GIA also notes that CVD requires lower upfront equipment cost than HPHT but may need subsequent treatment to improve colour. What that difference means commercially is best evidenced by how Chinese listed companies themselves divide the work. Red Arrow's 2025 annual report describes a deliberate two-route posture — HPHT plus CVD, covering two complementary product segments — and flags rising demand from integrated circuits, new-energy vehicles and high-end optics for high-purity, large-size, high-performance, low-cost functional diamond. Sifangda's 2025 annual report states that majority-held subsidiary Henan Tianxuan owns proprietary MPCVD synthesis and processing equipment together with CVD diamond growth process technology, and has batch production capability for high-quality, large-size, ultra-pure CVD diamond, with products applicable to jewellery, precision tools, optical windows and chip heat sinks; elsewhere in the same report Tianxuan is described as focusing on self-developed MPCVD equipment and CVD diamond synthesis processes. Sinomach Precision's 2025 annual report positions MPCVD around large-size single-crystal and polycrystalline diamond production lines plus heat spreaders and optical windows. Worldia's 2025 annual report summary lists its CVD diamond functional-material products as diamond-film acoustic devices, diamond heat sink material, diamond optical windows, diamond tool material, and boron-doped diamond-film coated electrodes. The HPHT camp, meanwhile, still lives in industrial and consumer grit: Liliang Diamond's product structure is lab-grown diamond, diamond single crystal and diamond micropowder; and Huifeng Diamond's 2025 interim report, citing China Customs, gives first-half 2025 diamond micropowder exports (HS 71051020) of 2.037 billion carats — a billions-of-carats scale that by itself tells you micropowder is a different business, nowhere near the scale on which gem-grade rough is sold stone by stone. One caveat: CVD lateral size is constrained by the seed substrate, and the literature routinely discusses quality loss in edge overgrowth (for instance a 2019 Materials study by a Shandong team on 300-torr homoepitaxy, reporting a 27.12 μm/h growth rate at 3% methane and 1150°C, and noting that the homoepitaxial region inherited from the HPHT substrate has higher crystal quality than the lateral edge overgrowth). 'CVD can simply be scaled up without limit' is not a fact.

05Roster 1: the listed players and where each sits in the chain

This section gives company name, current ticker, listing venue, registered and office address, and what each does in the diamond chain — all from periodic filings, listed by ticker, unordered and unranked. Addresses follow the filing's own fields: where a report has a 'registered address' field we give it, where it only has an 'office address' or a 'company domicile' we give only that field, without merging fields or back-filling street numbers. It deliberately carries no revenue, profit or year-on-year figures: those refresh quarterly and any third-party restatement of them goes stale fast, so rely on each company's latest periodic report. Red Arrow (000519, Shenzhen Main Board): superhard materials run through Zhongnan Diamond Co., Ltd. in Nanyang; the listed entity's registered address moved from Xiangtan, Hunan to 569 Liangxiang Road, Nanyang, Henan on 13 March 2026, and its office address is inside the Zhongnan Diamond compound at 1669 Zhongjing North Road, Nanyang. The annual report records Zhongnan Diamond as an MIIT-designated chain-leader enterprise and national-level green factory, states that it continues to consolidate first place in global industrial diamond market share and first place domestically in cubic boron nitride (both 'first' claims are the company's own statements in its annual report and are not third-party verified), and notes exports to more than 40 countries and regions; on functional diamond, the report says its 220 GHz high-power microwave diamond window development project was selected for the 'China Good Technology' project library. Liliang Diamond (301071, ChiNext, Zhecheng, Shangqiu): registered and office address are both Zhecheng County Industrial Cluster Zone (postcode 476200), while the board-secretary and securities-representative contact address given in the annual report is Danyang Avenue, East Industrial Cluster Zone, Zhecheng County — the two are not the same address. Its base is HPHT, with three product families: lab-grown diamond, diamond single crystal and diamond micropowder. On R&D, one widely mis-cited item needs correcting against the filing: in the 2025 annual report's major R&D project table, the 10×10 mm CVD diamond high-quality growth process programme is marked completed (targeting VS or VVS clarity, near-colourless to colourless type IIa); the cooling-related project marked in progress is the development and preparation of high-efficiency heat dissipation material for high-power electronic devices, whose process is described as microwave plasma CVD rather than written as MPCVD, targeting 7×7 to 20×20 mm sizes, 0.3–3.0 mm thickness and 1800–2200 W/(m·K) thermal conductivity. Huanghe Whirlwind (600172, Shanghai Main Board, Changge, Xuchang): the 2025 annual report summary gives a contact address of 200 Renmin Road, Changge; products span superhard materials and products plus superhard composite materials and products, including industrial diamond, lab-grown diamond, grinding wheels, cutting tools, drill bits and saw blades, used in diamond tool manufacturing, jewellery and ceramics processing among others. Yu Diamond (formerly 300064, Zhengzhou Huajing Diamond): delisted, no longer an A-share company — the single most important status correction in this article. Its 2020 financial statements received a disclaimer of opinion, its shares carried a delisting risk warning from the open of trading on 28 April 2021, the CSRC opened an investigation into suspected disclosure violations, and the pre-penalty notice found net assets overstated by RMB 1.856 billion at end-2019; the shares entered the delisting consolidation period on 6 June 2022 (trading under the abbreviation 'Jingang Tui'), with an expected final trading day of 24 June 2022, and were struck from the board the trading day after that period expired. Any roster that still lists Yu Diamond as a listed company is out of date. Sifangda (300179, ChiNext, Zhengzhou): its 2025 annual report gives both registered and office address as 109 Tenth Street, Zhengzhou Area (Jingkai) of the Henan Pilot Free Trade Zone. Three product families: polycrystalline diamond compacts for oil, gas and construction, composite superhard products for precision machining, and CVD diamond, the last sitting in majority-held subsidiary Henan Tianxuan Semiconductor, which the annual report calls a CVD diamond producer with an advantageous position in domestic equipment scale (the company's own statement in its annual report, not third-party verified). In the R&D table, the third-generation MPCVD equipment programme and MPCVD mosaic tiling are both marked in progress. Worldia (688028, STAR Market; the listed entity is Beijing Worldia Diamond Tools Co., Ltd.): core business is ultra-high-precision and high-precision cutting tools plus superhard products; diamond functional materials are described in the annual report summary as a new growth curve, with a technology stack covering CVD diamond growth, laser micro/nano precision machining of superhard materials, and thinning plus mirror polishing of ultra-thin diamond plates. Sinomach Precision (002046, Shenzhen Main Board; registered address 6 Fenghua Road, Luoyang Hi-Tech Development Zone, office address 121 Kexue Avenue, New Materials Industrial Park, Zhengzhou, with the Third Abrasives Research Institute in Zhengzhou): superhard materials run through Sinomach Diamond, and the annual report's wording is that the operating vehicle is Sinomach Diamond, 67% held by the company, with the remaining 33% held by Henan Provincial New Materials Investment Group. The same report's capital-reserve movement note records that Sinomach Diamond's minority shareholder, Henan Provincial New Materials Investment Group Co., Ltd., injected additional capital into Sinomach Diamond, and states that after the superhard materials business was moved into Sinomach Diamond in March–April 2025 the shareholding of Sinomach Precision and the New Materials Group in Sinomach Diamond remained at 67%:33%. A separate entity should not be confused with that minority shareholder: the annual report records that Sinomach Precision's own controlling shareholder became China National Machinery Industry Corporation (Sinomach) in September 2008. The annual report states that the company independently developed MPCVD diamond crystal preparation and processing technology, achieved batch production, has the capability to develop MPCVD diamond production equipment itself, and has built a new high-power MPCVD production line for large-size single-crystal and polycrystalline diamond; it further states that its MPCVD large single-crystal diamond sits in the domestic first tier on both capacity scale and technical strength (the company's own statement in its annual report, not third-party verified), and its R&D table places microwave plasma CVD (MPCVD) equipment at the small-batch production stage. Sinomach Diamond's own website lists both HPHT presses (cubic and belt-type) and vapour deposition equipment (MPCVD systems) alongside ultra-high-thermal-conductivity CVD diamond heat spreaders and high-transmission CVD diamond optical windows (that page is dated 21 April 2025; accessed 26 July 2026). Huifeng Diamond (920725, Beijing Stock Exchange, Zhecheng, Shangqiu): there is an easy stale-data trap here — the company's current ticker is 920725, used on the cover of its 2025 annual report, while the older 839725 appears on earlier documents such as its 2025 interim report and should be labelled as the then-current code when cited. On addresses we follow the filing's own fields: that report has no separate 'registered address' field; the office address it gives is 10 Beihai Road, Zhecheng County Industrial Cluster Zone (the board secretary's contact address is also 10 Beihai Road), while the company domicile stated in its financial-statement notes is 'Zhecheng County Industrial Cluster Zone, Beihai Road' with no street number — we do not back-fill the office address's street number into the domicile, and we do not say 'registered and office address are both'. It develops, produces and sells synthetic single-crystal diamond micropowder, micropowder derivative products and CVD diamond materials, with main products being diamond micropowder, crushed and shaped diamond material, and CVD lab-grown diamond; the annual report records that it co-drafted the national standard for synthetic diamond micropowder as a superhard abrasive, was named an MIIT 'little giant' specialised and sophisticated enterprise in December 2020, had its synthetic single-crystal diamond micropowder designated a sixth-batch manufacturing single-champion product by MIIT in November 2021, and passed the sixth-batch single-champion enterprise re-review in 2025. The report also discloses that its Baotou project under construction is primarily for CVD diamond heat sink plates, semiconductor functional material preparation and lab-grown diamond production, and marks the R&D programme on high-grade MPCVD diamond film preparation as concluded.

06Roster 2: the MPCVD equipment and CVD material players

Only trade-media round-ups are available on this side, and the reason is visible in the roster itself: of the 30 companies listed below, Zhejiang Jingsheng Mechanical & Electrical is a listed company (the article prints ticker 300316 directly after its name), Henan Tianxuan is a majority-held subsidiary of the listed Sifangda, and Jinggong Ruiyi Technology (Henan) is described by the article as a wholly-owned subsidiary of Sinomach Precision's Zhengzhou Third Abrasives Research Institute; for every other company here we found no listing disclosure, which means no periodic-report discipline applies to them. CMPE's 27 March 2026 round-up of MPCVD equipment and domestic players catalogues the domestic field. Company names below are transcribed verbatim from that article's entry headings, prefixes such as 'Shenzhen' and 'Foshan' included; years are copied from its body text — not every entry gives a founding year, and a few give some other date, which is flagged in place — and both the ordering and the regional grouping follow the article: Beijing Zuowen Technology, Beijing Yunmao Technology; Tianjin Motai Technology (the article gives no founding year, saying only that Motai 'began developing batch-process MPCVD equipment in 2015', so 2015 is not a founding year); Xi'an Demengte Semiconductor, Xi'an ENTASK Semiconductor (September 2020); Shandong Liguan Microelectronics Equipment (2013); Carbon Equation Semiconductor Equipment Manufacturing (Shanxi) — the body text of the same article renders this as Carbon Equation New Materials (Shanxi) Co., Ltd., founded 2021; Hebei Plaisman Diamond Technology; Henan Tianxuan Semiconductor (2021), Jinggong Ruiyi Technology (Henan), Henan Tanzhen Xincai Technology (the article says 'established January 2023'), Zhengzhou Shilei Technology (2021), Zhengzhou Tianhong Diamond Technology (July 2016); Anhui Jutan Machinery; Chengdu Wenzheng Technology (2019), Chengdu Huayu Microwave Technology, Chengdu Wattsine Electronic Technology; Wuxi Yuanwenxi Technology, Jiangsu Zhuoyuan Semiconductor (2018), Wuxi Yongliang Carbon Technology; Zhejiang Jingsheng Mechanical & Electrical (the article prints 300316 after the name), Hangzhou Jingchi Mechanical & Electrical (2021), Naxing (Ningbo) Semiconductor, Hangzhou Xinshiqi Technology (the article says its origins date to 2011); Shanghai Boshiguang Semiconductor Technology, Shanghai Dongbei Vacuum Equipment (2001); Foshan Haiguang Intelligent Technology; Shenzhen Uniplasma Plasma Technology (2016), Shenzhen Chaoci Robot Technology (2017), Shenzhen Youde Diamond New Materials (2021). This must be said plainly: the list is a media round-up, not a ranking, and we have not independently verified each company's founding year or current operating status; anyone using it for sourcing should check current business-registry and company-website information. Beyond dedicated equipment builders, a second identity needs separating out: material producers that build their own reactors. Sifangda's 2025 annual report says Henan Tianxuan owns proprietary MPCVD synthesis and processing equipment and focuses on using self-developed MPCVD equipment; Sinomach Precision's 2025 annual report says the company has the capability to develop MPCVD diamond production equipment itself, and Sinomach Diamond sells both MPCVD systems and HPHT presses commercially. In China, in other words, 'who makes equipment' and 'who makes material' are not mutually exclusive sets. A third category is suppliers of microwave sources, chambers and control systems, which trade media catalogue separately.

07Sourcing view: which category of supplier fits which need

Gem-grade large rough and polished stones: go to material producers on the MPCVD single-crystal route. Check per-stone carat weight together with the three-dimensional rough size (length x width x height, not carat alone — and do not take the word 'largest' at face value, since within one supplier's own size table the largest by volume need not be the thickest), the colour and clarity distribution rather than one hero sample, whether the material is type IIa, whether third-party grading reports from IGI or GIA can be supplied stone by stone, monthly output and lot-to-lot consistency, and whether post-growth colour treatment is required (GIA notes explicitly that CVD material may need subsequent treatment to improve colour). Industrial abrasive, micropowder and single crystal: go to the Henan HPHT complex. Check grit distribution against the national standard for synthetic diamond micropowder as a superhard abrasive, single-lot volume and lead time, and customs experience (micropowder is HS 71051020). Composite superhard products and tooling (PDC/PCBN): go to composite-blank and tool makers, and first settle whether the downstream is oil and gas drilling or precision machining, since impact and thermal requirements differ. Optical windows and heat spreaders: decide single crystal versus polycrystalline first, which is the trade-off between area and near-interface conductivity; then check size and thickness tolerance, surface roughness and flatness, bondability and metallisation adhesion, and the measurement temperature behind any quoted thermal conductivity (a room-temperature figure and an operating-temperature figure are not the same number). Semiconductor substrates: settle homoepitaxial versus heteroepitaxial, target size (inch-scale versus millimetre-scale), dislocation density and doping capability; Chinese university teams have publicly stated they can supply 1–2 inch large-area high-quality single-crystal diamond substrates. Buying equipment: pin down microwave frequency (2450 MHz and 915 MHz are two different power and size routes), power class, effective growth-surface diameter and achievable crystal height, chamber architecture, control system and stability metrics (MTBF, chamber pressure stability, continuous full-load hours), spare parts and service radius, and whether a process package is included (gas recipe, seeds, substrate preparation). One general rule: establish first whether the counterparty is a dedicated equipment builder, a material producer running its own reactors, or a component and microwave-source supplier, because delivery responsibility differs completely across the three. Unlisted companies' capacity and size claims are self-reported and not constrained by periodic filings, so ask for samples and third-party test reports.

08Where ENTASK sits on this map

Xi'an ENTASK Semiconductor Technology Co., Ltd. was founded in September 2020 in Xi'an (founding date and headquarters per the CMPE round-up cited above), with registered capital of RMB 20 million (supplied by the company, not independently verified by a third party), and sits in the map above as a Shaanxi company doing both MPCVD equipment and CVD material — one of the two Xi'an MPCVD equipment companies in that round-up. On the equipment side it has Gen-4, Gen-4.5 and Gen-5 platforms, with Gen-4.5 and Gen-5 currently on sale, built around its in-house E-MG010K microwave source (2450 MHz, 10 kW/15 kW) and the InsightAction and WiseAction control systems. On the material side, rough is predominantly rectangular, with standard sizes of 20×15×9.5, 21×17×9.7 and 24×18×10 mm and non-standard sizes of 30×30×15 mm and 35×35×12 mm, in D–E colour, VVS–VS clarity, type IIa; there are also single-crystal optical windows from 20×20 to 45×45 mm at 0.5–1.2 mm thickness, and single-crystal heat spreaders from 20×20 to 30×30 mm (single crystal only, no polycrystalline). The quality system is ISO 9001:2015, and a sample IGI grading report exists for a 10.80 ct D VVS2 type IIa stone (report number LG756504660). Two published invention patent applications are on record, CN119269411A and CN120178750A (published-application status at the China National Intellectual Property Administration, not granted patents). The company states that its market coverage spans mainland China plus India, the Middle East, Europe and North America (supplied by the company, not independently verified by a third party). All of the equipment specifications, material specifications, registered capital and market coverage above are supplied by the company and have not been independently verified by a third party. On size ceilings there is exactly one usable statement: 35×35×12 mm is the largest size the company has delivered at equivalent D–E colour, VVS–VS clarity, type IIa grade (supplied by the company, not independently verified by a third party). That 'largest' needs its basis stated: it is largest by growth-face area and by volume — a 35×35 mm growth face is 1,225 mm² and the volume is 14,700 mm³, both greater than the 900 mm² and 13,500 mm³ of the non-standard 30×30×15 mm — but on thickness alone, the 15 mm of 30×30×15 mm exceeds the 12 mm of 35×35×12 mm. Buyers selecting on thickness should read the thickness column directly and not read 'largest size' as 'thickest'. It should also be stated plainly: ENTASK makes no claim to have broken any published weight record — the rough carat figures in public reporting (190 ct CVD, 156.47 ct and 150.42 ct HPHT, each at a different grade and evidence level; see our article on the largest CVD diamond rough) are all far above the formats above — and nothing in this section constitutes a claim about output, capacity, market share or ranking.

09Notes on denominators and the limits of this piece

First, this article deliberately carries no revenue, profit or year-on-year figures for any company. Two reasons: such numbers refresh quarterly and third-party restatements of them are almost guaranteed to go stale; and the question this article answers — which Chinese companies work in CVD diamond and MPCVD, and what each of them does — needs only company names, current tickers, locations and business descriptions. The only year-on-year percentage anywhere in this piece is an industry statistic, not company financials: China's 2024 lab-grown diamond output was up 144.44% on 2023, per People's Daily Online of 30 September 2025 citing the 2024 report on the development of China's jewellery industry, with period and source stated in the text. Readers who need financials should go directly to the latest periodic reports as disclosed on the exchanges and on cninfo. Second, the business descriptions, addresses, designations and R&D project statuses quoted here all come from 2025 annual reports; Huifeng Diamond's micropowder export figure comes from its 2025 interim report and is first-half 2025 customs data, with the period stated in the text. Addresses follow each filing's own fields: Liliang Diamond's registered/office address and its board-secretary contact address are not the same address, and we give them separately; Huifeng Diamond's 2025 annual report has no separate 'registered address' field, so we give only the office address it states (10 Beihai Road, Zhecheng County Industrial Cluster Zone) and the company domicile from its financial-statement notes (Zhecheng County Industrial Cluster Zone, Beihai Road, no street number), without merging them or back-filling the street number. Third, several inconsistent share-of-market denominators are in circulation: 63% (China's 2024 lab-grown diamond output as a share of global output, per People's Daily Online citing the 2024 report on China's jewellery industry), over 90% (China's total diamond output as a share of global output, per Huifeng's 2025 annual report), over 80% (Henan's share of national capacity, per Huifeng's 2025 annual report; Henan's share of national synthetic diamond output, per Red Arrow's 2025 annual report), and 50% (China's share of world lab-grown diamond output, per Liliang Diamond's 2025 annual report). Those denominators are lab-grown output, all-diamond output, intra-China capacity and intra-China output respectively, and are not interchangeable. Fourth, every 'first / only / leading / advantageous position / first tier' formulation appearing in this article is the relevant company's own statement in its own annual report or on its own website; we quote and attribute without independent verification, and none of them is this article's ranking judgement. Specifically: Zhongnan Diamond's first place in global industrial diamond market share and domestic cubic boron nitride (Red Arrow annual report); the Third Abrasives Research Institute as the only comprehensive research institute in China's abrasives industry (Sinomach Precision annual report); Sinomach Precision's MPCVD large single crystal in the domestic first tier (Sinomach Precision annual report); Henan Tianxuan's advantageous position in domestic equipment scale (Sifangda annual report); and Dialine as the first company in China to industrialise diamond wire and the first listed Chinese company to break foreign technology monopoly in diamond wire mass production (Dialine website, accessed 26 July 2026). Company websites can be rewritten at any time and are not publicly archived, so both websites cited here — Dialine's 'About' page and Sinomach Diamond's MPCVD business page (page dated 21 April 2025) — carry an access date of 26 July 2026. Fifth, the MPCVD equipment roster comes from a trade-media round-up, is not a ranking, and has not been checked company by company against business registries or operating status: of the 30 companies listed, only three listing relationships can be established from the article itself (Zhejiang Jingsheng Mechanical & Electrical, which the article tags 300316; Henan Tianxuan as a majority-held subsidiary of the listed Sifangda; and Jinggong Ruiyi Technology (Henan), which the article describes as a wholly-owned subsidiary of Sinomach Precision's Zhengzhou Third Abrasives Research Institute), while for the rest we found no listing disclosure and their capacity and specification claims are largely self-reported. Nor are all the years in that roster founding years — for Tianjin Motai, for instance, the article says it 'began developing batch-process MPCVD equipment in 2015', which we flag in place. Sixth, this piece passes no judgement on any company, is not investment advice, and does not attempt to answer 'who is biggest' — the publicly available metrics are not yet consistent enough to support that comparison. Where anything here conflicts with a more recent disclosure, the company's latest periodic report and official announcements govern.

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