Gem-quality synthetic diamonds are more available in today’s jewelry marketplace than ever before, causing both interest and concern among jewelers about the material’s nature and whether it can be identified by gemologists or gemological labs. GIA has studied synthetic or ‘man-made’ diamonds extensively over the past 30 years, and we know a great deal about how they’re produced and can be recognized. While synthetic diamonds are lab-grown or factory produced, their chemical and physical properties correspond very closely to those of natural diamonds. Some people might refer to synthetic diamonds as imitations or simulants, but this is incorrect. Imitations like cubic zirconia or synthetic moissanite—which only look like diamond—have very different chemical and physical properties. This allows trained gemologists to recognize them readily. However, synthetic diamonds are much harder to detect.