The transparency of an emerald is every bit as important as that of its origins, as the Gübelin Gem Lab advocates. With its in-house Emerald Paternity Test, the maiden service under the gem house’s Provenance Proof label, invisible tagging of stones are done as soon as they are unearthed. The technology embeds detailed information such as the mining location, the miner and the mining time for individual crystals prior to any cleaning or sorting.
Central to the process are customised DNA-based nanoparticles introduced within the stones; these penetrate a gem’s fissures and adhere to its walls. The applied ethanol-based carrier liquid evaporates completely, and the tagging process is complete. As the rough emerald crystals undergo cutting, polishing and re-oiling stages, a sufficient quantity of DNA tags in the nanoparticles will remain to be read out and decoded at any point in its life.
Perhaps most impressive of all is that given the diameters of the nanoparticles — 100 nanometers, or in a more common unit prefix 0.0001 millimetres — they are undetectable even under the best optical microscopes and render no optical drawback whatsoever. Therefore, at such time that the finished emerald finally makes its way to a jewellery piece and is presented to a customer, it is as intact and clear as expected.
In typical non-partisan Gübelin style, the Emerald Paternity Test is available to the whole industry. Assuring a a jewellery house or end client is ideal, but the implications of paternity testing extend to assisting industry and trade organisations along with government regulatory bodies monitor the sustainability and responsible practices of the gemstone industry.