Lab diamond and moissanite

This shelf is not a diamond shop. The notes below are so a gift conversation does not mix up a diamond, a laboratory-created diamond, and a simulant.

What the word diamond means

The US rule at 16 CFR 23.12 says a diamond is a mineral consisting essentially of pure carbon crystallized in the isometric system, found in many colors. It states hardness 10, specific gravity approximately 3.52, and refractive index 2.42. The same section says it is unfair or deceptive to use the unqualified word "diamond" for an object that does not meet that definition.

Source: Electronic Code of Federal Regulations, 16 CFR 23.12, read 2026-10-03.

Laboratory-created diamonds

The Federal Trade Commission's brochure "In the Loupe" says a seller of laboratory-created diamonds should tell people they are not mined diamonds, using "laboratory-grown," "laboratory-created," "[manufacturer name]-created," or similar wording, immediately before the word "diamond" and equally conspicuous. It also says not to use those terms unless the product has essentially the same optical, physical, and chemical properties as a mined diamond. The CFR section above allows "cultured" for laboratory-created diamonds with those same properties only with a clear disclosure that the product is not a mined stone.

Source: Federal Trade Commission, In the Loupe: Advertising Diamond, Gemstones and Pearls, page dated July 2019, read 2026-10-03. And the CFR section linked above.

Moissanite is not that

GIA's article on imitation gems calls colorless synthetic moissanite a diamond imitation that became popular in the late 1990s. It gives moissanite a hardness of 9.25 on the Mohs scale and says that is very hard, although not as hard as diamond. It says moissanite has more than twice the fire of diamond and slightly more brilliance, and that it is doubly refractive, so a viewer can see a double image of the back facets. We are not adding a chemical formula. A GIA 4Cs page we tried returned an error, so it is not a source here.

The FTC brochure says thermal testers used to separate diamonds from cubic zirconia may not accurately identify moissanite, which it calls a laboratory-created gemstone that resembles a diamond, and that the stone may falsely register as a diamond on a thermal detector.

Source: Gemological Institute of America, An Introduction to Simulants or Imitation Gem Materials, read 2026-10-03. And the FTC brochure linked above.

If you sell or describe one

The FTC brochure says simulated or imitation diamonds should be described as "imitation," "simulated," or similar wording immediately before "diamond," so a shopper can see it is not a laboratory-created or mined diamond. This page is not telling you which stone to buy.

General information only. This is not professional gemological, appraisal, or shopping advice. Details can change. Confirm price, material, and delivery on the retailer page.