Diamond Terminology Guideline Introduction and Reference

Effective use of a clear and accessible terminology for diamonds, synthetics diamonds and imitations of diamonds by all sector bodies, organizations and traders.

This Diamond Terminology Guideline serves as a reference document for the diamond and jewelry trade when referring to diamonds and synthetic diamonds. It is built on two internationally accepted standards: the ISO 18323 Standard.

Consumer confidence in the diamond industry”) and the CIBJO Diamond Blue Book.


  • A diamond is a mineral created by nature; a “diamond” always means a natural diamond.
  • A synthetic diamond is an artificial product that has essentially the same physical characteristics as a diamond.
  • An imitation diamond, also named a diamond simulant, is an artificial product that imitates the appearance of diamonds without having their chemical composition, physical properties or structure.
  • A gemstone is a mineral of natural origin that is used in jewelry for reasons of combined beauty, rareness and intrinsic value.


  • When referring to synthetic diamonds: - Use one of the following authorized qualifiers when referring to synthetic diamonds: “synthetic”, “laboratory-grown” or “laboratory-created”. - Do not use abbreviations such as “lab-grown” and “lab-created”. - Do not use the following terms: “cultured diamonds” and “cultivated diamonds” as “cultured” and “cultivated” refer exclusively to organic/products. - Do not use the following terms: “real”, “genuine”, “precious”, “authentic” and “natural” as those apply exclusively to natural minerals and gemstones.


  • A diamond is natural by definition. Therefore, use the word “diamond” without a qualifier when referring to a diamond. If differentiation from synthetic diamonds is required, use the term “natural diamonds” as a term of equivalent meaning.
  • Do not use the following confusing expressions: “natural treated diamonds” and “treated natural diamonds”. Instead, simply use “treated diamonds”.


  • The leadership of AWDC, CIBJO, DPA, GJEPC, IDI, IDMA, USJC, WDC, and WFDB strongly recommend all traders, sector bodies and other organizations to comply with the guideline on all documents, websites and other means of communication that are intended to e.g. sell, buy and promote diamonds, synthetic diamonds, gemstones, gemological laboratory reports, diamond jewelry, and synthetic diamond jewelry.