CFR > Title 16 - Commercial Practices > CHAPTER I—FEDERAL TRADE COMMISSION > SUBCHAPTER B—GUIDES AND TRADE PRACTICE RULES (parts 17 to 260) > PART 23—GUIDES FOR THE JEWELRY, PRECIOUS METALS, AND PEWTER INDUSTRIES > 23.25—Misuse of the word “gem.”

23.25—Misuse of the word “gem.”

(a) It is unfair or deceptive to use the word “gem” to describe, identify, or refer to a ruby, sapphire, emerald, topaz, or other industry product that does not possess the beauty, symmetry, rarity, and value necessary for qualification as a gem.
(b) It is unfair or deceptive to use the word “gem” to describe any laboratory-created industry product unless the product meets the requirements of paragraph (a) of this section and unless such word is immediately accompanied, with equal conspicuousness, by the word “laboratory-grown,” “laboratory-created,” or “[manufacturer-name]-created,” “synthetic,” or by some other word or phrase of like meaning, so as to clearly disclose that it is not a natural gem.

Code of Federal Regulations

Note to § 23.25 : In general, use of the word “gem” with respect to laboratory-created stones should be avoided since few laboratory-created stones possess the necessary qualifications to properly be termed “gems.” Imitation diamonds and other imitation stones should not be described as “gems.” Not all diamonds or natural stones, including those classified as precious stones, possess the necessary qualifications to be properly termed “gems.”