The American Gem Trade Association (AGTA) has updated its Code of Ethics and released the 17th edition of its Gemstone Information Manual, introducing revised terminology and disclosure requirements for manufactured gemstones.

Under a policy approved by the AGTA board of directors in June 2026, members must use the term “synthetic” when describing manufactured materials that have essentially the same chemical composition, crystal structure, and physical and optical properties as their natural counterparts.

The revised policy states that “lab-grown” cannot be used on its own to describe a man-made gemstone. Retail jewellers may instead use “synthetic” or “man-made” alongside the gemstone name, such as “synthetic ruby” or “man-made sapphire.”

AGTA President Bruce Bridges said consistent terminology is important for consumer confidence and that the policy provides members with a standard for describing synthetic gemstones.

The move follows AGTA’s decision in 2024 to prohibit the sale or display of lab-grown diamonds and gemstones at its trade shows.

The association’s 17th Gemstone Information Manual also introduces three new treatment symbols: ASBL for assembled stones, including doublets and triplets; HR for heating with residue; and W for waxing.

The manual’s gemstone information chart has also been updated to identify irradiation and heat as common, stable treatments for pink morganite. Revised care guidance includes warnings against ultrasonic cleaning for certain gemstones, including jade and moonstone.

The terminology change is significant for the coloured gemstone trade, where disclosure and differentiation between natural and manufactured materials remain key issues across the supply chain.