(IDEX Online) - A buyer who thought they'd bagged a bargain 12.15-carat Kashmir sapphire was devastated to learn it was a near-worthless synthetic.The unnamed customer bought the oval modified step cut gem, set in a white metal ring, while travelling in Indonesia, complete with a "reputable" lab report.But they sent it for a lab test at GSI Mumbai after taking it for alterations at local jewelers, who were concerned it wasn't a genuine sapphire."Under magnification, numerous tiny gas-bubbles and curved striae could be seen clearly, typical of the flame fusion laboratory growth process," the lab said.The customer didn't disclose the price, but Kashmir blue, the most prized of all sapphires, typically cost $5,000 to $50,000 per carat depending on quality. Lab grown sapphires can cost just a few hundred dollars."Sellers may claim gemstones sold to be natural, may also offer laboratory reports to claim the authenticity of the gemstone at a discounted price," warned Deepa Srinivas, chief gemologist at GSI India."In this case, the fraudulent seller created a synthetic sapphire to match the specs on the lab report which led the client to trust the purchase. "It is important for tourists to be vigilant and to buy only from reputed stores or brands that sell gemstones with legitimate laboratory reports." Pic courtesy GSI.