Emerald, ruby, sapphire: coloured gemstones don't follow the same rules as diamonds. Here are the laboratories that authenticate them, and the traceability commitment behind every stone I offer.
See the available stonesThere's no universal 4C scale for coloured gemstones. Each laboratory assesses hue, saturation and brightness using its own terminology, and geographic origin often weighs more heavily on a stone's final value than clarity.
I have my coloured gemstones authenticated by the most respected laboratories in the trade, each with its own specialty:
The laboratory best known to the public, with an internationally recognised coloured-stone department.
Official site →Swiss academic reference institute, based in Basel, particularly for origin determination and treatment detection.
Official site →Founded in 1923 in Lucerne, one of the world's historic authorities for fine-jewellery coloured gemstones.
Official site →GRS GemResearch Swisslab, the reference for commercial colour nomenclature ("pigeon's blood", "royal blue").
Official site →Asian Institute of Gemological Sciences, in Bangkok, recognised expertise on stones of Asian origin.
Official site →Independent French laboratory, based in Paris since 2009, diamonds and coloured gemstones.
Official site →I work exclusively with RJC-certified suppliers (Responsible Jewellery Council) for my coloured gemstones, exactly as I do for my diamonds. This commitment guarantees a verified supply chain, from the supplier through to the stone you receive.
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