$594 million from China, and a prototype press at IIT Madras
India imported about $594 million of rough lab-grown diamonds from China and Hong Kong in FY2025-26. A 242 crore rupee programme at IIT Madras has now run a prototype HPHT press. Single source.
By The Diamonds Desk
What changed
India has completed successful trials of a domestically designed high-pressure high-temperature diamond press, and grew HPHT rough on it, according to a report published on 24 August by Diamond City, the Gujarati fortnightly that serves the Surat trade.
What it means
- Treat this as a machine that ran, not an industry that changed. A prototype press making good rough at a research institute is three separate distances from a Surat factory floor: a full-scale build, a yield anyone will underwrite, and a cost per carat that beats a Chinese press already amortised.
- November and December are the dates to hold this against, and if the announcement comes without a carat figure and a cost, it is a ribbon and not a result. The number worth watching is not the press.
- It is whether that $594 million import line is smaller in FY2026-27 than it is now.
Key figures
| rough LGD bought from China and HK, FY2025-26 | $594m |
|---|---|
| the research programme, 2023 budget | ₹242cr |
| programme as a share of one year's imports | ~4.9% |
| budget announcement to prototype trial | 3 yrs |
Source: InCent-LGD, IIT Madras
A press that ran
The machine is a prototype built by the India Centre for Lab-Grown Diamond, or InCent-LGD, under the 242 crore rupee research programme awarded to IIT Madras when the finance minister announced it in the 2023 union budget. This paper carries the item single-source and labels it so.
The report rests on unnamed industry and technical sources, InCent has made no statement of its own, and this desk found no English-language trade coverage of it at press time. The figures below are the outlet's; the arithmetic on them is this desk's.
The money is the part that scales. India bought roughly $594 million of rough lab-grown diamonds from China and Hong Kong in FY2025-26 on the same report's figures, which it converts to more than 4,900 crore rupees.
That implied rate of about 82.5 rupees to the dollar puts the 242 crore rupee programme at close to $29 million, or about 4.9% of a single year's import bill, on this desk's arithmetic and the outlet's own conversion rather than a market rate this desk has verified.
A research grant equal to one twentieth of one year's purchases is not a substitution plan. It is a licence to stop paying a licence.
The import bill against the programme · US dollars, millions
Source: InCent-LGD, IIT Madras
The bill it is aimed at
The next phase is already in motion and it has dates attached. Large components for a full-scale commercial press have been manufactured across units in north India and shipped to IIT Madras for integration, assembly and final testing, and the team is collecting feedstock from around the country to standardise raw material and process parameters.
Sources at the Gem and Jewellery Export Promotion Council put the indigenous technology and the raw-material trials in their final stage, with an official announcement of the capability likely in November and the first full-scale press expected complete by December.
Every one of those dates is an expectation reported through third parties, not a commitment anyone has published, and this desk prints them as such.
| Figure | |
|---|---|
| Rough Lgd Imports From China And Hk, Fy2025-26 | $594m |
| The Iit Madras Programme, ₹242 Crore | ~$29m |
Notes on this table
Both figures are from Diamond City's report of 24 August 2026. The dollar value of the programme is this desk's arithmetic on the outlet's own implied rate of about 82.5 rupees to the dollar, taken from its conversion of $594 million to more than 4,900 crore rupees, and not a market rate this desk has verified. Single-source item. Carat Capital graphics desk.
What HPHT holds that CVD does not
The gap it addresses is specific. India already holds a commanding share of world production by chemical vapour deposition, the other route to a grown stone, and Surat cuts and polishes more than 90% of the world's diamonds.
What it has not held is HPHT press capacity, where China's equipment base and scale have made it the supplier of record, and HPHT rough carries a premium for clarity and colour that CVD material does not automatically match.
A cutting industry that owns the polishing end of a supply chain and rents the growing end has one bill it cannot negotiate. That bill is the $594 million.
The story so far
Go deeper
Method
Both figures are from Diamond City's report of 24 August 2026. The dollar value of the programme is this desk's arithmetic on the outlet's own implied rate of about 82.5 rupees to the dollar, taken from its conversion of $594 million to more than 4,900 crore rupees, and not a market rate this desk has verified. Single-source item.