Surat: A Rs 242 crore lab-grown diamond research project at IIT Madras has successfully tested a prototype high-pressure high-temperature diamond press and produced good-quality HPHT rough diamonds, marking a significant step towards indigenous production.Three years after finance minister Nirmala Sitharaman announced the allocation in the 2023 Union Budget, the India Centre for Lab Grown Diamond (InCent-LGD) completed successful trials on a prototype high-pressure high-temperature (HPHT) diamond press, people familiar with the development said.Experts associated with the project said the trials delivered encouraging results for the performance of the press as well as the “recipe” of inputs used to grow diamonds. The prototype combined commercially available technology with research carried out by IIT Madras scientists.“Using the prototype, a good quality HPHT rough was grown by InCent. This also highlights how locally available material was successfully used to develop the product,” said a diamond industry expert aware of the progress.The project has now entered an advanced stage focused on building a full-scale HPHT press. Full-size components have been manufactured in North India and shipped to IIT Madras for integration and testing, sources said. The team is sourcing inputs from various parts of the country to standardise materials and process parameters.Sources in the Gem & Jewellery Export Promotion Council (GJEPC) said development of the HPHT technology and raw material trials are nearing completion. A formal announcement on the locally developed capability is expected in Nov. The development is expected to reduce India’s reliance on imported HPHT-grown lab-grown diamond roughs.India imported $594 million worth of rough lab-grown diamonds from China and Hong Kong in 2025-26. China remains a leading supplier because of its mature technology and large-scale HPHT production capacity.India produces substantial volumes of lab-grown diamonds through chemical vapour deposition (CVD) technology and has secured a strong market share. Industry participants consider domestic HPHT capability important because HPHT diamonds are valued for their clarity and colour. India’s polishing industry continues to play a key role in producing gem-quality stones.Industry stakeholders said development of the HPHT press along with compatible locally sourced raw materials would strengthen supply security and improve competitiveness.Experts involved in the project estimate that the full-scale HPHT press could be ready by the end of this year. The InCent team declined to comment.
