Most Utah Valley couples shopping for a ring now face the same first question: lab-grown or natural. The sales pitch for each side is easy to find. This page is about the two things that are not sales pitches: what federal rules say a lab-grown diamond is and how it must be described, and what the grading laboratories put on the report. We read the Federal Trade Commission's Jewelry Guides, GIA's announcements and IGI's report page on October 20, 2026.
For local jewelers, budgets, appraisals, insurance and the sizing trap, read our engagement rings guide. This page is the definitions and the paperwork.
What the FTC says a diamond is
The FTC's Guides for the Jewelry, Precious Metals, and Pewter Industries (16 CFR Part 23) are the federal rules on how jewelry may be described. Three parts matter here.
The definition. Section 23.12(a): "A diamond is a mineral consisting essentially of pure carbon crystallized in the isometric system." Nothing in that definition says where the carbon crystallized.
The disclosure. Section 23.25 says it is unfair or deceptive to use a stone's name for a laboratory-made stone unless the name is preceded, with equal prominence, by a qualifier such as "laboratory-grown" or "laboratory-created." Words like "laboratory-grown," "laboratory-created" or "synthetic" may be used with a natural stone's name only when the product has essentially the same optical, physical and chemical properties as that stone.
"Cultured." Section 23.12(c)(3) allows "cultured" for laboratory-created diamonds with essentially the same properties as mined diamonds, but only with a clear and conspicuous disclosure that the stone is not mined.
Simulants are a different thing. Stones that only imitate a diamond, such as moissanite or cubic zirconia, must be called "imitation" or "simulated," and the Guides note that "faux" by itself is not an adequate disclosure.
So, plainly: a lab-grown diamond is a diamond, and the seller has to say "lab-grown" (or "laboratory-created") every time it uses the word. A ring advertised only as "diamond" should be a natural stone.
What GIA's report now says
GIA, the Gemological Institute of America, is one of the largest diamond grading laboratories. It changed how it describes lab-grown stones twice in the last few years.
- June 2025: GIA announced it would stop using natural-diamond color and clarity grades for lab-grown diamonds. Its reason: more than 95% of lab-grown diamonds fall into a "very narrow range of color and clarity."
- October 1, 2025: the new service launched, per GIA's August 26, 2025 release.
Under the new system, a D-to-Z lab-grown diamond gets one of two descriptive assessments:
| GIA category | Clarity | Color | Polish and symmetry | Cut (round brilliants) |
|---|---|---|---|---|
| Premium | VVS or higher | D | Excellent | Excellent |
| Standard | at least VS | E to J | Very Good (symmetry Good for fancy shapes) | Very Good |
A stone that misses any Standard minimum receives no GIA assessment at all. GIA laser-inscribes the girdle with "Laboratory-Grown" and the assessment number, and returns a printed document with the stone. GIA's fee to the trade is $15 a carat, $15 minimum, with a 0.15-carat minimum size. Lab-grown reports GIA issued before the change remain valid.
What this means when you shop: a GIA document on a lab-grown stone now tells you "Premium" or "Standard," not "F, VS1." If a seller quotes 4Cs grades for a lab-grown stone, the report probably comes from another laboratory, or predates October 2025.
What IGI's report says
IGI, another large laboratory, still grades lab-grown diamonds with 4Cs language. Its lab-grown report grades color on the D-to-Z scale, clarity from IF to I at 10x magnification, and a cut grade for round brilliants (with polish and symmetry for all shapes). It may note the growth method, HPHT or CVD, and any post-growth treatment in the comments.
Laboratories are not interchangeable, and a grade from one is not the same measurement as a grade from another. Compare stones graded by the same lab, and read every line of the report, including the comments.
The 4Cs, briefly
From GIA's own explanation:
- Color runs from D (colorless) to Z (light yellow or brown) for natural diamonds.
- Clarity has 11 grades, from Flawless (no inclusions or blemishes visible at 10x) through very, very slightly included, very slightly included, slightly included and included.
- Cut describes how well the proportions and polish handle light: brightness, fire and scintillation.
- Carat is weight, not size: one carat is 0.2 grams, divided into 100 points.
A buyer's checklist
- Ask "lab-grown or natural?" and get the answer printed on the receipt.
- Ask which laboratory graded it, and get the report itself, not a summary.
- Check the inscription against the report number with a loupe; a jeweler will show you.
- Compare like with like: two lab-grown stones from the same lab, or two natural stones from the same lab.
- Get the return, upgrade and buyback terms in writing, especially for lab-grown stones, where no one publishes resale values.
- Insure the ring once you buy it. Our engagement rings guide covers appraisals and insurance.
Our Just Engaged guide covers what to do once the ring is on, and the used dresses, decor and rings guide covers buying and selling secondhand rings. For the whole wedding budget, see the Utah County Wedding Cost Study.
Frequently Asked Questions
Is a lab-grown diamond a real diamond?
Is moissanite or cubic zirconia a lab-grown diamond?
What does 'cultured diamond' mean?
Does GIA still grade lab-grown diamonds D to Z?
What does GIA 'Premium' mean on a lab-grown diamond?
Do other labs still give lab-grown diamonds 4Cs grades?
How do I know a stone is lab-grown?
Do lab-grown diamonds hold their value?
Sources
The facts in this guide were checked against these sources. Hours, fees and rules change, so confirm anything time-sensitive with the source before you go. How we make Provo.com.
- 16 CFR Part 23, Guides for the Jewelry, Precious Metals, and Pewter Industries, eCFR / Federal Trade Commission. Checked October 20, 2026.
- New descriptive terminology for laboratory-grown diamonds, GIA. Checked October 20, 2026.
- Updated laboratory-grown diamond services to launch October 1, GIA. Checked October 20, 2026.
- Diamond quality factors (the 4Cs), GIA. Checked October 20, 2026.
- Lab-grown diamond report, IGI. Checked October 20, 2026.
