Natural vs. Lab Created vs. Simulated Gemstones

Natural vs. Lab Created vs. Simulated Gemstones.
November 29, 2005
People buying or selling gemstones should read FTC 'Guides for the Jewelry, Precious Metals, and Pewter Industries.' The following quote from the Guide is particularly important:
Guides for the Jewelry, Precious Metals, and Pewter Industries
Effective April 10, 2001
23.23 Misuse of the words ruby, sapphire, emerald, topaz, stone, birthstone, gemstone, etc.
(a) It is unfair or deceptive to use the unqualified words ruby, sapphire, emerald, topaz, or the name of any other precious or semi-precious stone to describe any product that is not in fact a natural stone of the type described.
(b) It is unfair or deceptive to use the word ruby, sapphire, emerald, topaz, or the name of any other precious or semi-precious stone, or the word stone, birthstone, gemstone, or similar term to describe a laboratory-grown, laboratory-created, (manufacturer name)-created, synthetic, imitation, or simulated stone, unless such word or name is immediately preceded with equal conspicuousness by the word laboratory-grown, laboratory-created, [manufacturer name]-created, synthetic, or by the word imitation or simulated, so as to disclose clearly the nature of the product and the fact it is not a natural gemstone.
(c) It is unfair or deceptive to use the word laboratory-grown, laboratory-created, (manufacturer name)-created, or synthetic with the name of any natural stone to describe any industry product unless such industry product has essentially the same optical, physical, and chemical properties as the stone named.
In brief:
(1) A natural gemstone is mined and is produced by nature.
(2) A lab created ruby, emerald, diamond, etc. has the same chemical, physical, and optical properties of the natural ruby, emerald, or diamond, etc.
(3) A simulant (or imitation) merely resembles the natural stone.
For example, a lab diamond is carbon crystallized in the cubic system, hardness 10, specific gravity approximately 3.52, index of refraction 2.417 and optical dispersion 0.044. See FTC Guide 23.11, and Dana, New Mineralogy.
A stone is NOT a lab diamond if it is lab created and resembles a diamond. A stone is NOT a lab tanzanite if it is lab created spinel, glass, or cubic zirconia (CZ) and is violet colored.
Ph.D. Graduate Gemologist (GIA)