Lab Grown Diamonds


Gem-quality laboratory-grown diamonds (LGDs) have been on the market for several decades. For over 60 years, LGDs have been grown and used for industrial purposes. Today, gem-quality LGDs are growing as a product category available to consumers. LGDs are created with special equipment in a laboratory. They have essentially the same optical, chemical and physical properties as mined diamonds. There are currently two methods for producing lab-grown diamonds: a high-pressure, high-temperature (HPHT) process and chemical vapor deposition (CVD). WHAT’S INSIDE 1 What Are Lab-Grown 2 FTC Definition 3 Risk to Jewelers 4 Best Practices 6 Detection Devices 7 Key Messages Exclusively for JA Members: Laboratory-Grown Diamonds Guide | 2 Lab-grown diamonds cannot be distinguished from natural diamonds by a simple visual inspection. However, LGDs do have certain features that help distinguish them when inspected under magnification or using ultraviolet light:

  • Lab-grown diamonds often have metallic inclusions and scattered pinpoints that appear differently than in natural diamonds. There may be an absence of natural inclusions. A microscope under high power can reveal these characteristics.
  • Microscopy can also reveal linear growth patterns that are not characteristic of natural diamonds.
  • Using ultraviolet light, some lab-grown diamonds exhibit a glow after the light is turned off (phosphorescence).
  • Review this GIA article for more information on identifying LGDs.


According to the Federal Trade Commission (FTC) Guides for the Jewelry, Precious Metals and Pewter Industries, the word “diamond” can refer to both a diamond that has been created by nature and mined by man and a laboratory-grown diamond, since a laboratorygrown diamond has the same “optical, physical and chemical properties as mined diamonds.” When describing and marketing lab-grown diamond products, the FTC requires producers to “clearly and conspicuously convey that the product is not a mined stone.” Allowed terminology:  laboratory-grown  laboratory-created  “[manufacturer’s name]-created” but not “[manufacturer’s name]-grown”  words or phrases of like meaning, such as lab-grown and lab-created  “cultured” can be used if the term is immediately accompanied by the words above, such as laboratory-grown, laboratory-created, or other terms of like meaning Not Recommended:  “synthetic,” because many consumers mistakenly believe “synthetic” means an artificial product such as cubic zirconia, which lacks a diamond’s optical, physical and chemical properties. A note on natural, mined diamonds: A diamond sourced from nature and not treated needs no qualifying language and can be referred to as “diamond” or “natural diamond” according to the FTC.