Introduction
Transparency is the foundation of trust in diamond transactions. When a buyer purchases a diamond — whether for an engagement ring, an anniversary, or any other purpose — they have a right to know exactly what they are getting. For lab-grown diamonds, this means clear, unambiguous disclosure of the stone's laboratory origin at every stage: at the point of sale, on the grading report, and inscribed on the stone itself.
This article covers the regulatory requirements, the grading report format, the physical inscription, and what a buyer should expect from an ethical seller.
FTC Disclosure Requirements
The US Federal Trade Commission (FTC) Jewelry Guides establish the baseline rules for how lab-grown diamonds must be described and sold:
Mandatory disclosure. A lab-grown diamond must be disclosed as laboratory-grown, laboratory-created, or equivalent at the point of sale. The origin qualifier cannot be omitted. Selling a lab-grown diamond as simply "a diamond" without disclosure is a violation.
Qualified language required. Every reference to a lab-grown diamond in advertising, marketing, point-of-sale materials, and verbal communication must include an appropriate qualifier: "laboratory-grown diamond," "lab-created diamond," or equivalent.
No misleading terms. Terms that suggest a lab-grown diamond is natural (e.g., "real diamond" without qualification, "mined diamond" applied incorrectly) or that suggest it is an imitation (e.g., "fake," "synthetic" in consumer contexts) are prohibited or discouraged.
The 2018 FTC revision was a landmark update. It removed "natural" from the baseline definition of diamond, acknowledging that lab-grown stones are genuine diamonds. But it simultaneously reinforced that origin disclosure is mandatory — the consumer must know whether the diamond formed in the Earth or in a laboratory.
The GIA Laboratory-Grown Diamond Report
The GIA issues a dedicated report format for lab-grown diamonds: the Laboratory-Grown Diamond Report (LGDR). This report was updated in 2020 to include full 4Cs grading, bringing it into alignment with the level of detail provided on natural diamond reports.
What the LGDR Contains
- 4Cs grading: Colour, clarity, cut (for round brilliants), and carat weight — the same grading scales and criteria applied to natural diamonds
- Growth method: The report identifies whether the stone was grown by CVD or HPHT
- Treatment disclosure: If post-growth treatments were applied (e.g., HPHT treatment to improve colour), the report notes: "May include post-growth treatments to change the color"
- Measurements: Precise dimensions in millimetres
- Proportions: For round brilliants, the same proportions diagram used on natural diamond reports
- Clarity plot: Diagram of inclusion locations and types (if applicable)
Visual Distinction
The LGDR is designed to be visually distinct from the GIA's natural diamond reports. The layout, colour scheme, and prominent labelling ensure that anyone examining the report can immediately identify it as a lab-grown diamond document. This prevents confusion at resale or when reports change hands.
Before 2020
Prior to the 2020 update, the GIA graded lab-grown diamonds on a more limited descriptive scale rather than the full 4Cs letter/number grades. The current full-grading format provides consumers with directly comparable quality information across both natural and lab-grown categories.
Girdle Inscription
The GIA inscribes the girdle of every lab-grown diamond it grades with a laser inscription that includes:
- "Laboratory-Grown" — the origin identifier
- The report number — linking the physical stone to its documentation
The inscription is microscopic — invisible to the naked eye but readable under standard magnification (10x loupe or microscope). It provides a permanent, non-removable identification marker that travels with the stone regardless of how many times it changes hands.
Inscription Scope
Stones above 0.20 ct are inscribed as standard practice. The inscription is applied after grading and before the stone is returned to the submitter.
Can It Be Removed?
Technically, a girdle can be repolished to remove a laser inscription. However, this reduces the stone's carat weight, alters its measurements, and invalidates the grading report. Any reputable jeweller or appraiser would flag a stone whose dimensions do not match its report — making inscription removal both impractical and ethically indefensible.
IGI and Other Laboratories
The GIA is not the only laboratory that grades lab-grown diamonds. The International Gemological Institute (IGI) currently dominates the lab-grown diamond certification market by volume and also provides full 4Cs grading with growth method disclosure.
Other laboratories — HRD Antwerp, GCAL, and others — also grade lab-grown diamonds with varying levels of detail. The key elements that any reputable lab-grown diamond report should include:
- Clear identification as a lab-grown diamond
- Growth method (CVD or HPHT)
- Full 4Cs grading
- Disclosure of any post-growth treatments
- A girdle inscription linking the stone to the report
Seller Obligations
An ethical and legally compliant seller must:
- Disclose origin before or at the point of sale — not buried in fine print
- Provide a grading report from a reputable laboratory
- Ensure the stone is inscribed with a laboratory-grown identifier
- Use correct terminology — "lab-grown diamond," "laboratory-created diamond," or equivalent
- Disclose treatments — if the stone has been treated post-growth, this must be communicated
A buyer encountering a seller who is vague about origin, reluctant to show a grading report, or who describes a lab-grown diamond without the appropriate qualifier should treat these as warning signs.
Frequently Asked Questions
Is it illegal to sell a lab-grown diamond without disclosing it?
Under FTC Jewelry Guides, selling a lab-grown diamond as a natural diamond or without disclosing its laboratory origin is a deceptive trade practice. Enforcement is handled by the FTC, and violations can result in legal action.
What does the GIA report for a lab-grown diamond look like?
The GIA Laboratory-Grown Diamond Report includes full 4Cs grading (colour, clarity, cut, carat weight), growth method (CVD or HPHT), treatment disclosure, measurements, and a proportions diagram. It is visually distinct from natural diamond reports to prevent confusion.
Do all lab-grown diamonds have girdle inscriptions?
All lab-grown diamonds graded by the GIA above 0.20 ct receive a "Laboratory-Grown" girdle inscription. Other major labs follow similar practices. Ungraded lab-grown diamonds may not be inscribed, which is one reason buying a graded stone with a report is important.
Which lab should I look for on a lab-grown diamond report?
GIA and IGI are the most widely recognised for lab-grown diamond grading. The GIA is generally considered the most consistent in grading standards. IGI grades a larger volume of lab-grown stones. Either provides the essential information: origin, 4Cs, treatment disclosure, and inscription.
Summary
Disclosure is not optional. Lab-grown diamonds must be identified as laboratory-grown at the point of sale, on the grading report, and through a permanent girdle inscription. The GIA Laboratory-Grown Diamond Report provides full 4Cs grading, growth method identification, and treatment disclosure in a format visually distinct from natural diamond reports. These safeguards exist to protect the buyer — ensuring that when you purchase a diamond, you know precisely what it is, how it was made, and what the report tells you about its quality.