Disclosure & Listing Policy

We commit to ensuring transparent and accurate communications with regard to the provenance of coloured gemstones listed on the Gembridge Platform – and the characteristics that make them unique.

We expect our Members to make the same commitment, and in signing up to the Gembridge Platform, Members are also committing to this policy.

When Members complete a Listing Form, it is their responsibility to fully disclose material facts about the gemstone they wish to sell. If Members are in any way unsure about the provenance or attributes of a stone, they must ensure that the proper expertise is employed to remove all doubt. It is in every Member’s interest to strictly adhere to this requirement. Building trust takes time; losing it can be immediate – and irreversible. Members who do not uphold transparent and full disclosure will be barred from listing on Gembridge.

Factual Representation

All Precious Articles posted on the Platform must be accurately and completely represented at the time of listing. This includes photos, videos, descriptions, measurements, weights, and available certifications/reports. This also includes omission of information, particularly regarding undisclosed enhancements, gemmological reports, inclusions and condition and general quality issues.

Members’ descriptions must always be honest, factual and accurate. A Member must not misrepresent the nature, authenticity, treatment, origin, colour or clarity of any Precious Article. A Member’s written disclosure of their knowledge of treatments is mandatory, at the point of listing, in all documents (for example, a listing form, an invoice or a bill of sale) pertaining to each individual Precious Article or lot of gemstones. Examples of inaccurate and misleading information include, without limitation:

  • Describing obviously pink corundum as ruby.
  • Colour-correcting images to make stones look better than or different to their true appearance.
  • Stating that a stone is unheated if it has been heat-treated or if the Member is not sure that the stone has not been heat-treated.
  • Listing an emerald with a report stating a level or type of clarity enhancement which has been changed since the issuing of the listed report.
  • Describing stones which have or may have been treated as ‘natural’ without qualifying any relevant treatments.
  • Not disclosing beryllium treatment or other forms of diffusion where it may have or has occurred.
  • Not disclosing residues from heat treatment with flux where this treatment may or has taken place.
  • Describing sapphires that are only pink or orange, and not a mixture of both, as padparadscha.

Specific treatments are addressed at ‘TREATMENTS or ENHANCEMENTS’ below. 

Omission Of Information

As with any sale of goods, there are legal obligations for all parties concerned.

Full disclosure means sharing every commercially relevant detail about a gemstone. For example, a Member must mention if a stone has been enhanced in any way, and the nature and extent of its treatment. All reports pertaining to the stone must also be disclosed, even if several exist which are contradictory.

Personal Responsibilities Of Sellers And Buyers

It is the responsibility of the Seller to ensure that they have done their due diligence in investigating and clarifying potential treatments which are then clearly and accurately stated in any listings and sales communications. They must then represent each Precious Article accurately and fairly, according to best industry practices. Should any information be missing, Sellers should proactively look for documentary proof in order not to misrepresent the stone on the Platform. The onus is also on the Buyer to ensure they have all the information that they need to make a reasoned purchase decision.

To the best of their ability Members shall ensure that the gem materials they source and sell are mined and traded responsibly and ethically. Gemstones should not be sourced or processed using child labour, or in violation of any laws, and the health of all workers, including miners and cutters, must be respected, with a concern for protecting and restoring the environment. All Precious Articles must be obtained legally, not in association with smuggling or supporting illegal activities. Members must respect government embargoes within their respective countries and are responsible for staying updated on and following these legal obligations.

Gemmological Reports

Gembridge encourages listings accompanied by gemmological reports from established, reputable and respected gemmological laboratories. In the interests of transparency, we have high expectations of reports submitted to us. The laboratory name will be stated on the relevant listings, as well as the year it was produced. Any information given on reports in abbreviated or code form regarding treatments must be included in full on the listing by the Seller.

Generally we encourage reports less than five years old; ideally less than two years old for emeralds due to the cleaning, testing, and re-treating of emeralds being particularly common. It is the responsibility of the Seller to ensure that reports submitted are an accurate representation of the origin and treatment of all gemstones at the time of submission. Constant developments in gem testing technology, such as previously undetectable treatments, and new origin discoveries, demand regularly updated research and information, often necessitating the need for recent or even multiple reports.

As a further commitment to industry transparency and best practices, we retain the right to refuse to publish reports on Gembridge from unverified organisations without proven qualifications or track records, and any organisations posing as a better known laboratory through similar acronyms or visual marketing. All reports pertaining to the stone must also be disclosed, even if several exist which are contradictory.

Certain gemstones, such as padparadscha sapphires, should either be accompanied by a report or guaranteed by the Seller, due to the risk of undisclosed treatments. In some instances, such as for high value (blue) sapphires, multiple reports from respectable laboratories would be appropriate.


Visual imagery must be a truthful and accurate representation of each listing just as the description must be. Photographs and videos must not be colour corrected, improved or manipulated beyond attempting the closest realistic representation of a listing.

We reserve the right to reject imagery supplied by a Seller if it has been enhanced to give an unrealistic representation of colour, or to hide inclusions and other visible flaws. Given the variability of phone and computer screens, it is essential that the source imagery is as faithful to a gemstone’s true colour as possible.

Treatment or Enhancements

It is commonly recognised that gemstones are susceptible to a multitude of different treatments (also known as ‘enhancements’), but that, as long as such treatments do not cause or mask ongoing damage, instability or danger to the gemstone or to the consumer, the majority of treatments are acceptable as long as fully and accurately disclosed. Coloured gemstone treatments include (but are not limited to): heating, heating with additional diffused elements, heating with pressure; oil, resin or other clarity enhancements; filling with foreign elements such as glass; dying, bleaching, coating, impregnation; irradiation.

Gembridge expects the highest standards of trading practices and gemstone quality, and will accept, with full disclosure, gemstones which have undergone various forms of heating, including with additional diffused elements or pressure, and gemstones which have undergone clarity enhancement with oil, resin, or wax, as long as fully disclosed. It is the Seller’s responsibility to investigate and fully disclose any information relating to treatments before listing, and if this information cannot be supplied at the point of sale, it is the Seller’s responsibility to communicate this clearly to the Buyer.

Gembridge does not however, accept material which has undergone glass or fracture filling, material which has been dyed, bleached, coated, or impregnated, material which could be considered composite, material which could become or be considered dangerous or unstable (with or without the removal/reversal of the treatment) or material simply too low grade as not to be considered good commercial quality.

Some treatments are notoriously difficult to detect, such as (low temperature) heat treatment and the irradiation of certain gem materials; Sellers must commit to due diligence in discovering and 4 7 of disclosing such treatments wherever possible, and equally never to falsely describe items as not having undergone treatment unless they can categorically justify this with lab testing or supply chain proof.

Gembridge follows, and expects all members also to adhere to, the guidelines for nomenclature and disclosure set out by CIBJO – The World Jewellery Confederation (“CIBJO”). For further details, see

Listing Guidelines

In general, Gembridge will accept for listing on the Platform any high quality gemstones over US$1,000 per lot and fulfilling the following criteria. All lots must be properly and honestly represented as per the Gembridge Charter and Disclosure Policy.

Gembridge retains the right to refuse upload onto the site or remove lots at their discretion.

Accepted For Sale on Gembridge:

  • Mainstream natural coloured gemstone varieties of high commercial quality. High commercial quality/gem quality includes gems with high transparency, minor inclusions, of attractive and saleable colour varieties, with a professional level of cutting, and with either none or acceptable and fully disclosed treatments.
  • Varieties include: gem corundum, including ruby, sapphire, padparadscha, fancy and star sapphire; gem beryl, including emerald, aquamarine, morganite; gem tourmaline varieties, including paraiba, red or pink ‘rubellite’, green, blue and particolour varieties; gem spinel; gem zoisite, including blue/purple tanzanite, pink, green, yellow, orange and parti-colour varieties; gem chrysoberyl, including alexandrite and cat’s-eye; imperial topaz; certain gem garnet varieties, including demantoid, tsavorite, colour-change; precious opal
  • Other gem varieties of fine quality and unique size

Not Accepted For Sale On Gembridge:

  • Stones which are not naturally formed, i.e. synthetic or labgrown material.
  • Stones which have been fracture-filled with glassy substances, including but not limited to rubies and sapphires.
  • Stones which have been dyed, bleached, coated, or impregnated, which could be considered composite, or which could become or be considered dangerous or unstable, such as some irradiated stones.
  • Stones under 6 on Mohs Scale of hardness.
  • Stones considered so common as to have a lower commercial value, including but not limited to most quartz varieties (rose or smoky quartz, rock crystal, carnelian, chrysoprase); certain garnet varieties (pyrope-almandine).
  • Stones displaying any form of physical instability, by way of quality or treatment (including but not limited to fractures and fissures) or simply too low grade as not to be considered good commercial quality.

All Precious Articles must be described and represented honestly and faithfully.

Photographs and videos must visually represent the gem as truthfully as possible and descriptions must include all relevant information, factually guaranteed by the Seller, and with no misrepresentation by omission. Treatments must be disclosed at point of listing and suspected treatments verified and disclosed before upload. Quality observations, including noticeable inclusions and fractures, should be noted on our online listing form and in any verbal or other forms of communication.

All Precious Articles on the Platform will be listed or taken down at Gembridge’s sole and absolute discretion. All listings are to abide by these Listings Guidelines principles.

Gembridge reserves the right to change these guidelines at any time, and any exceptions to these guidelines will be made at the discretion of


In the event of any non-compliance of this Policy by any Member (“Defaulting Member”) whether intentional or otherwise, Gembridge may suspend, investigate, remove and/or terminate access of the Defaulting Member to their account on the Platform and the Services, and the Defaulting Member’s registration as a Customer. Gembridge shall also be entitled to remove the Defaulting Member’s listings and other content from the Platform, to prohibit and ban the Defaulting Member from creating another account or using another individual or Legal Person to access the Platform and/or use the Services.

Where the non-compliance with this Policy results in a conflict with another Member, Gembridge may mediate the dispute and take the following actions:-

  • (a) where the Seller or Consignor has failed to comply with this Disclosure Policy, and the Buyer or Consignee is in possession of the Precious Article, Gembridge may invoice the Seller or Consignor for, and the Seller or Consignor shall bear, the costs and expenses incurred in the delivery of the Precious Article, and the insurance costs, where applicable to:-
    • the Buyer;
    • the Buyer’s selected Viewing Room;
    • the reputable testing facility pursuant to Term 3.27 of the T&Cs;
    • the Consignment Location;
    • return the relevant purchase price to the Buyer or Consignor; and
    • any other actions as set out in the T&Cs.
This disclosure and listing policy (this “Policy” or “Disclosure Policy”) sets out the expectations and obligations of all Members. Gembridge reserves the right to amend, modify and/or supplement this Policy at any time without prior notice to the Members. Gembridge will publish the updated Policy on the Platform. Unless otherwise defined within this Policy, capitalised terms used shall have the same meaning as defined in our terms and conditions (“T&Cs”). For the purposes of our policies, the reference to “Members” is a reference to Gembridge’s Customers

For any enquires contact us via our Contact page.