About Erebaur

Erebaur was founded by Maxime Perriard, who publishes it from Fribourg, Switzerland. It has two sides: this free encyclopedia of precious stones, and a service that finds stones for clients and has each one tested by an independent laboratory.

The full legal details are in the privacy policy and the terms of use.

Every chapter ends with the sources it was written from. They are institutional, and of five kinds:

• Peer-reviewed journals and the gemmological research literature
• Government and intergovernmental bodies
• Standards and trade-rule bodies: CIBJO, LMHC, ISO and the US Federal Trade Commission
• Museums and the other institutions that hold the stones
• What mining companies and auction houses disclose about their own operations and sales

No chapter cites Wikipedia. Where no primary record exists and a chapter cites the trade press instead, that citation is flagged on the review list with the reason.

A claim the writers could not fully verify against an institutional source is not dropped or softened in silence. It goes on an open review list, flagged for a person to check. Claims on that list now: 493, grouped by chapter. The list is kept with the encyclopedia’s source files; it is not shown on the chapter pages.

The whole encyclopedia was last reviewed on September 19, 2026. Every chapter was re-sourced against institutional references and checked against them, and the corrections were made in all eight languages.

That checking is editorial. No independent gemmologist has reviewed the encyclopedia yet. When one does, their name and credentials will appear on this page.

The encyclopedia is free to read and is paid for by advertising from Google AdSense, which appears only on the pages listed here as carrying ads.

There are no paid placements and no sponsored content. No company has paid to be mentioned, linked or ranked, and the encyclopedia carries no affiliate links.

Erebaur also runs two paid services. The sourcing service works for a buyer, who pays Erebaur to find a stone and have it tested by an independent laboratory. The Register publishes stones offered by their owners; there Erebaur acts for the seller and is paid by the seller when a sale completes.

The encyclopedia does not recommend sellers. The companies, laboratories and auction houses it names are there because they are part of the trade it describes. Stone pages link to the sourcing service.