16 CFR 23.17: Misuse of the words “brilliant” and “full cut.”

It is unfair or deceptive to use the unqualified expressions “brilliant,” “brilliant cut,” or “full cut” to describe, identify, or refer to any diamond except a round diamond that has at least thirty-two (32) facets plus the table above the girdle and at least twenty-four (24) facets below.

Note to § 23.17:

Such terms should not be applied to single or rose-cut diamonds. They may be applied to emerald-(rectangular) cut, pear-shaped, heart-shaped, oval-shaped, and marquise-(pointed oval) cut diamonds meeting the above-stated facet requirements when, in immediate conjunction with the term used, the form of the diamond is disclosed.