Ahmedabad: Inexpensive synthetic diamonds will no more be passed off as natural sparklers in Gujarat’s Surat city, the world’s largest diamond cutting and polishing centre.

The Surat-based, state-sponsored Indian Diamond Institute, a project of the Gems and Jewellery Export Promotion Council, now has a centre to detect laboratory-cultured stones mixed with small (melee) natural diamonds.

The first synthetic Diamond Detection and Resource Centre (DDRC) is equipped with the world’s first Automated Melee Screening (AMS) device, manufactured by the De Beers Group for detecting and screening small synthetic stones from 1 cent to 20 cent and with the speed of 360 stones per hours.

According to Pankaj Parekh, vice-chairman, GJEPC, traders can walk in with their diamonds and check for their authenticity by paying nominal charges. The charges for screening diamonds in sizes ranging from 1 to 20 cents at the DDRC are in the range of Rs120 to Rs350 per carat.

Sources say China and Singapore are the centres for manufacturing synthetic rough diamonds using the chemical vapour deposition and a chemical process in the laboratories. The diamonds are sold to dealers in Hong Kong, China and Singapore for bulk supplies in India’s processing centres like Surat, Bhavnagar, Amreli (in Gujarat) and Mumbai