The CIBJO Blue Books are a series of authoritative reference manuals published by CIBJO, the World Jewellery Confederation, establishing internationally harmonised standards for the nomenclature, grading, treatment disclosure, and ethical trading of gemstones, pearls, precious metals, and related materials. Adopted by national trade associations, gemmological laboratories, and regulatory bodies across more than forty countries, the Blue Books function as the closest equivalent the global gem trade possesses to a unified rulebook — defining what a stone may be called, what treatments must be disclosed, and how synthetic and simulant materials must be distinguished from their natural counterparts. They are periodically revised to reflect advances in treatment technology, new synthetic production methods, and evolving trade consensus, making them a living document rather than a fixed code.

Background and the Role of CIBJO

CIBJO — an acronym derived from its French name, Confédération Internationale de la Bijouterie, Joaillerie, Orfèvrerie des Diamants, Perles et Pierres — was founded in 1926 and is headquartered in Geneva. It operates as an umbrella body representing national jewellery trade associations, bringing together manufacturers, retailers, laboratories, and allied industries. Its mandate is explicitly international: to facilitate cross-border trade by ensuring that a ruby described and sold in Bangkok carries the same definitional weight as one described and sold in Antwerp or New York. The Blue Books are the primary instrument through which CIBJO fulfils that mandate.

The designation "Blue Book" refers to the physical and digital volumes themselves, each dedicated to a specific material category. The principal volumes in current use cover diamonds, coloured gemstones, pearls, coral, precious metals, and gemmological instruments. Each volume is structured to address nomenclature first — establishing which names are permissible and under what conditions — before moving to treatment disclosure requirements, grading terminology, and broader ethical trade obligations.

Structure and Content of the Coloured Gemstone Volume

For practitioners in the coloured-stone trade, the Coloured Gemstone Blue Book is the most directly relevant volume. Its framework rests on several foundational principles:

• Nomenclature. The Blue Book specifies which species and variety names are acceptable in commerce and which qualify as trade names requiring clarification. It distinguishes natural stones from synthetic stones and from simulants, and mandates that these categories be clearly communicated at every stage of the supply chain. A synthetic ruby, for instance, must always be identified as synthetic; the unqualified word "ruby" is reserved for the natural mineral.
• Treatment disclosure. The Blue Book requires disclosure of any treatment that is not permanent, that significantly affects value, or that requires special care. Treatments that have become so universal and stable as to be considered standard practice — such as the heating of most commercial sapphires and rubies — are acknowledged, but the volume still requires that the absence of heat treatment be disclosed when a stone is untreated, given the premium such stones command. More invasive or less stable treatments, including fracture filling with glass or resin, beryllium diffusion, and surface coating, require explicit disclosure at the point of sale.
• Grading terminology. The Blue Book does not mandate a single universal colour or clarity grading scale for coloured stones in the way that the diamond volume addresses cut and clarity grades, reflecting the inherent complexity of grading a heterogeneous category. It does, however, define the outer boundaries of acceptable descriptive language and cautions against the use of misleading qualifiers.
• Country-of-origin claims. The Blue Book addresses origin nomenclature with care, acknowledging that origin designations such as "Burmese" or "Kashmir" carry significant market value while noting that such claims must be substantiated by appropriate laboratory documentation.

Treatment Disclosure Philosophy

The Blue Book's approach to treatment disclosure is grounded in a principle of proportionality: the more a treatment affects a stone's durability, appearance, or value, the more explicit the disclosure obligation. This philosophy aligns broadly with the approach taken by the United States Federal Trade Commission's Guides for the Jewelry, Precious Metals, and Pewter Industries (commonly called the FTC Guides) and with the disclosure codes published by the American Gem Trade Association (AGTA), though the three frameworks differ in jurisdictional scope and precise wording.

Where the Blue Book distinguishes itself from national frameworks is in its explicit international orientation. The FTC Guides carry legal weight only within the United States; AGTA codes bind only AGTA members. The Blue Book, by contrast, is designed for adoption across national boundaries, and its language is deliberately framed to be translatable and applicable in jurisdictions with differing legal traditions. National associations that adopt the Blue Book as their standard — as many European and Asian trade bodies have done — effectively import its disclosure requirements into their own codes of practice.

The Blue Book also addresses the disclosure chain: it is not sufficient for a dealer to disclose a treatment to a retailer if that retailer does not pass the information to the end consumer. The obligation to disclose travels with the stone through every commercial transaction.

Relationship to Other Standards

The CIBJO Blue Books exist within an ecosystem of overlapping but distinct standards. The most important points of comparison are:

• FTC Guides (United States). A regulatory framework with legal enforceability in the US market. The FTC Guides and the CIBJO Blue Books share many underlying principles but differ in legal status and in certain definitional specifics — for example, in how they handle the term "natural" and in their treatment of laboratory-grown diamonds.
• AGTA Gemstone Enhancement Disclosure Codes. A voluntary industry code binding on AGTA members, widely respected in the US coloured-stone trade. The AGTA codes use a lettered classification system (A through F and beyond) to categorise treatments by type and invasiveness, a granular approach that complements rather than duplicates the Blue Book framework.
• ISO Standards. The International Organisation for Standardisation has published standards relevant to gemstone testing and jewellery hallmarking. CIBJO maintains liaison status with ISO and has worked to align Blue Book definitions with relevant ISO documents where possible.
• Laboratory reports. Major gemmological laboratories — including the Gemmological Institute of America (GIA), Gübelin Gem Lab, and the Swiss Gemmological Institute (SSEF) — issue reports that reflect, and in many cases helped to shape, the treatment disclosure language codified in the Blue Books. Laboratory report language and Blue Book definitions have evolved in dialogue with one another.

Revisions and Current Status

CIBJO updates the Blue Books through a committee process involving member associations, scientific advisers, and laboratory representatives. Revisions have addressed, among other developments, the rise of beryllium diffusion treatment in corundum (first widely documented in the early 2000s), the proliferation of glass-filled rubies in the commercial market, and the rapid growth of the laboratory-grown diamond and coloured-stone sectors. The most recent editions of the Blue Books are available through CIBJO's official website and are distributed to member associations for integration into their national trade standards.

The Blue Books do not carry direct legal enforceability in most jurisdictions — they are trade standards rather than statutes — but their adoption by national associations and their citation by regulatory bodies in trade disputes gives them considerable practical authority. In markets where no national standard exists, the Blue Book frequently serves as the default reference for arbitrating nomenclature and disclosure disputes.

Significance for the Trade

For gemmologists, dealers, and retailers operating across borders, familiarity with the CIBJO Blue Books is a professional baseline. The volumes provide a common vocabulary that reduces the risk of misrepresentation arising from linguistic or cultural differences in how treatments are described. They also provide a defensible standard: a dealer who can demonstrate compliance with Blue Book disclosure requirements is in a far stronger position in any trade dispute than one who cannot. For consumers, the Blue Books represent the international trade's collective commitment to transparency — an acknowledgement that the value of a gemstone is inseparable from accurate knowledge of what it is and what has been done to it.

Further Reading

• CIBJO Blue Books (official CIBJO portal)
• GIA Gems & Gemology — Beryllium Diffusion in Corundum
• AGTA Gemstone Enhancement Disclosure Codes