Analysis & Grading

Disclosing Treated or Laboratory-Grown Gem Material to GIA

When submitting items to GIA for analysis and grading services, you are required to disclose any treated or laboratory-grown gem material.

At the core of GIA’s mission is its commitment to protect the gem-buying public – whether consumer or trade – by providing the research, education, and global quality standards needed to accurately and objectively assess gemstone quality. This commitment helps ensure trust and stability in the marketplace by instilling confidence in the gem materials bought and sold there.
The proliferation of highly sophisticated processes that manipulate the quality and value of gemstones threatens to undermine that confidence and destabilize markets if those processes are not detected and disclosed. GIA relies on rigorous research, advanced instrumentation and a global suite of best practices to identify and detect known laboratory-grown and treated diamonds submitted for service.
GIA’s ability to respond quickly to new developments, however, depends in part on the cooperation of its clients, who are the first lines of defense in helping to identify new treatments or laboratory-grown gem materials that enter the marketplace. For this reason, GIA requires its clients to disclose their knowledge – or even suspicion – that their gem material has undergone any form of treatment or synthesis when they submit it to the laboratory. If a client does not know whether or not a stone is HPHT-treated, GIA requests that the client make this known to the GIA Laboratory.
The vast amount of data GIA collects on the stones it services enables the Institute to identify trends and patterns. GIA will discontinue business with clients who exhibit a pattern of intentionally submitting treated or manufactured gem material without prior disclosure.
The overwhelming majority of GIA clients operate with integrity and good faith; GIA does not terminate clients for isolated instances.  
Every diamond submitted to GIA is tested to determine whether it is in fact a natural diamond, or if known treatments have been used to enhance its appearance to manipulate value. Reports are not issued for simulants or those diamonds that have undergone unstable treatments, such as fracture filling or coating.  While reports may be issued for diamonds that have been laser drilled or HPHT processed, these stable treatments are prominently disclosed on the report. GIA laser-inscribes the girdles of diamonds it identifies to be laboratory grown or HPHT processed as an added precaution for disclosure and identification.