16 CFR Part 23, Guides for the Jewelry, Precious Metals, and Pewter Industries; Project No. G711001
I don't think the term "cultured" should be used in reference to Laboratory-created/synthetic diamonds. Since all the laboratory created synthetic gem material commence with a "starter" crystal, it would not make sense to introduce a term that has been used in connection with the Cultured Pearl Industry; the result would simply create more confusion on the part of the industry, and ultimately, the final end-use, the consumer. Though "laboratory-created" may sound too technical, and a bit "Frankenstein-ish," it would be more correct/proper to apply this to synthetic diamonds.