Definition and misuse of the word “diamond.”
16 C.F.R. § 23.12
in effectEffective: 2024-07-01(a) A diamond is a mineral consisting essentially of pure carbon crystallized in the isometric system. It is found in many colors. Its hardness is 10; its specific gravity is approximately 3.52; and it has a refractive index of 2.42.
(b) It is unfair or deceptive to use the unqualified word “diamond” to describe or identify any object or product not meeting the requirements specified in the definition of diamond provided above, or which, though meeting such requirements, has not been symmetrically fashioned with at least seventeen (17) polished facets.
(c) The following are examples of descriptions that are not considered unfair or deceptive:
(1) The use of the words “rough diamond” to describe or designate uncut or unfaceted objects or products satisfying the definition of diamond provided above; or
(2) The use of the word “diamond” to describe or designate objects or products satisfying the definition of diamond but which have not been symmetrically fashioned with at least seventeen (17) polished facets when, in immediate conjunction with the word “diamond,” there is either a disclosure of the number of facets and shape of the diamond or the name of a type of diamond that denotes shape and that usually has less than seventeen (17) facets (e.g., “rose diamond”).
(3) The use of the word “cultured” to describe laboratory-created diamonds that have essentially the same optical, physical, and chemical properties as mined diamonds if the term is qualified by a clear and conspicuous disclosure (for example, the words “laboratory-created,” “laboratory-grown,” “[manufacturer name]-created,” or some other word or phrase of like meaning) conveying that the product is not a mined stone.
Source: eCFRURL: https://www.ecfr.gov/api/versioner/v1/full/2024-07-01/title-16.xmlFetched: 7/26/2026