Surat: The Diamond City, the global hub for natural diamond cutting and polishing and one of the world’s major centres for lab-grown diamond (LGD) production, is now focussed on becoming a leading lab-grown diamond jewellery manufacturing hub as well. While there have been allegations of lab-grown diamonds being passed off as natural diamonds in jewellery, a new and troubling practice is now surfacing — the use of moissanite, a synthetic stone — in jewellery sold as having lab-grown diamonds.The Indian Diamond Institute in Surat, an institute sponsored by the Union commerce ministry, found moissanite being used in jewellery sold as being LGD. This was detected when jewellery pieces were brought for to IDI’s gemmological laboratory for testing.“Every week we find at least one LGD jewellery piece where a moissanite stone has been used. Moissanite is much cheaper than LGDs and this is dangerous,” said Samir Joshi, director of IDI.Experts say moissanite is not a diamond and should not be sold as a diamond. “Some labs are certifying moissanite in the same way as LGDs and natural diamonds, mentioning their colour and clarity. This is a misleading practice,” Joshi said.Moissanite is a synthetic stone and is made in a factory. Moissanite does not have physical and optical properties matching LGD, while LGD’s optical and physical properties match those of natural diamonds.“In established jewellery manufacturing units, quality control is the key element. Testing and certification at every stage is the common practice which prevents dishonest practices such as the use of moissanite in LGD jewellery. If it is being done by anyone, it should be exposed,” said Amit Korat, president of the Surat Jewellery Manufacturers Association (SJMA).It should be noted that moissanite is sold by its size, in millimetres, compared to carat parameters used in diamonds. To make moissanite attractive, some gem and jewellery businesses get their colour and clarity certification done to confuse customers.
