Synthetic Opal Ring Buying Guide: What to Know Before You Invest When buying a Synthetic Opal Ring, it’s advisable to get it tested in a proper gemological laboratory and get a certificate of the stone’s authenticity from that lab. The reason for this is reputed gemological laboratories (like GIA, American Gem Society, ICA GemLab, etc.) provide all the details about the stone in their certificate of authenticity, like the stone’s origin, its cut, weight, color, and the treatments that the stone might have undergone. Also, gemological laboratories can quickly tell if your synthetic opals are imitation stones or not. Gemologists working at these gemological laboratories have professional tools for checking the gemstone, and they know the different ways you can check the stone.