The Emerald Paternity Test

The Gübelin Gem Lab is proud to introduce to the gemstone industry the Emerald Paternity Test, a technology to prove the provenance of emeralds back to the exact mine.

Provenance Proof Emerald Paternity Test

Why is traceability important?

The Emerald Paternity Test enables all stakeholders to work towards the realisation of their goals of transparency. So far, companies in the jewellery industry embracing ambitious transparency goals faced limitations when it came to the exact origin of the gemstones they used in their products. They had to rely on a mixture of trust and self-declaration by mining companies, lacking an independent proof of provenance.With the availability of the Emerald Paternity Test, such a proof is now available for all stakeholders within the gemstone industry. The Emerald Paternity Test is the first of a series of technologies and services dedicated to bringing more transparency into the gemstone industry, united under the Provenance Proof label.The right of using the technology is subject to a Code of Conduct, defining the use and application of the technology.

View the Code of Conduct here.

What is the technology?

Recent advances in nanotechnology and the customisation of DNA has enabled invisible tagging of various materials.
We have customised DNA-based, nano-sized particles to suit the specific needs of the gemstone industry. The particles have a diameter of about 100 nanometres or 0.0001 millimetres. Our nanoparticles are invisible even to the best optical microscope and do not induce any optical effect whatsoever.

Information on the mining location, the miner and the mining time is encrypted and stored in the DNA, and encapsulated in a sphere of amorphous silica to resist the influence of cutting, polishing and repeated treatment. By means of a carrier liquid, these particles are applied on the rough emerald crystals, penetrating even the tiniest fissures, and tightly adhering to their walls. The nanoparticles can be retrieved, the information contained in the DNA read out and decoded at a later stage, disclosing the paternity of the emerald.

How does it work?

The process typically starts in the mine. The rough crystals are tagged with the nanoparticles before any cleaning or sorting is undertaken. The application of the tracer technology in the mine is handled by an independent auditor.

The nanoparticles penetrate the fissures in the emerald and adhere closely to the surface. The applied ethanol-based liquid evaporates completely within a few minutes. The tagging process is already complete after this step.

Experience has shown that a sufficiently big number of DNA tags remain in the fissures during cutting, polishing and re-oiling processes, so it is usually possible to determine their origin at a later date.                                        

During the sale of the final piece in a retail shop, the Provenance Proof label and potential paternity test inspire trust and bring to the customer additional confidence in the jewel.

Whenever required, the stone can be submitted to an authorised lab to conduct the paternity test. And the client gets transparency about the exact place where the emerald was unearthed.

Download the brochure to learn more.

Who benefits?

The Emerald Paternity Test is available to the entire industry.

Mining companies and cooperatives

Being at the source, they unearth the rough gemstones and initiate the journey of the gemstone along the supply chain.

Industry organisations & NGOs

Industry and trade associations, NGOs and other organisations can use this technology to facilitate and check the implementation of policies and standards in the industry.


Governmental bodies can use the technology to promote and monitor their domestic production, control exports and distinguish their gems from other origins.

Jewellery brands

Jewellery houses, jewellery manufacturers and retailers can prove to their customers their commitment to the values of transparency and sustainability, which they embrace, setting them apart from their competitors.


The end consumer gets an insight into the social, environmental, ethical and health standards which are pursued at the birthplace of the gemstone used in the final jewellery piece.

Frequently asked questions

How are the particles inserted into the stone?

The emeralds are immersed into an ethanol-based liquid containing the nanoparticles. The suspended nanoparticles penetrate eye-visible, microscopic or even submicroscopic fissures, and adhere to the walls of all these fissures. The exact chemical mechanism behind this process is a proprietary procedure protected with an international patent.

What are the nanoparticles made of?

The nanoparticles used for the emerald paternity test consist of a synthetic DNA fragment, encapsulated into amorphous silica.As a biological molecule, DNA is not a very stable material, and degrades when exposed to sunlight, heat or humidity. To protect it from such degradation, it needs to be protected. In our nanoparticles, the DNA is encapsulated into silica, comparable to the process of fossilization. Silica (SiO2) is the most abundant molecule in the earth’s crust. The type of silica we are using for our nanoparticles are identical to the silica that forms natural opal.                            

Why are you using DNA?

We are using DNA as a medium to store client-specific information, inserted in the stone. DNA is nature’s favorite method of storing information in extremely small volumes of space, and as such successfully tested throughout the evolution. The nature of the DNA structure allows for an infinite number of unique codes to be written, making is suitable for a long-term, global application.

Are the particles harmful?

The synthetic DNA sequences used in our nanoparticles are identical to natural DNA fragments as they are naturally contained in different plants, such as fruits or vegetables. Through daily intake of food, humans’ digestion is perfectly used to digest even large volumes of DNA. Nanoparticles that accidentally get swallowed are therefore not causing any known health risk. And yes, our nanoparticles are perfectly vegan!
The amorphous silica used for our nanoparticles could not be proven to pose a health risk if swallowed or inhaled. Even those people that are working with the nanoparticles on a daily basis, for example when applying the particles to the rough crystals, are not exposed to any known risk according to the current state of knowledge. As the nanoparticles are suspended in a liquid, the nanoparticles are not airborne and therefore not prone to cause diseases such as silicosis. According to our research findings, the amount of nanoparticles getting airborne during the cutting process is usually moderate, and does not imply an increased health risk for the cutter. Likewise, no health risk arising from the nanoparticles in connection with the handling, setting, cleaning, oiling and finally wearing of the gemstones that contain our nanoparticles could be proven.. According to the requirements defined by European Commission and the Occupational Safety and Health Administration (OSHA), these nanoparticles contain nothing considered to be either persistent, bioaccumulative or toxic.                

Is tagging classified as a treatment?

It is up to the market or a trade authority such as CIBJO to decide if the Emerald Paternity Test is considered a treatment. We at the Gübelin Gem Lab believe that the application of the nanoparticles is not a treatment. A treatment implies that the appearance of the stone is altered in some way. Such an alteration due to application of the Emerald Paternity Test could not be proven by our studies. The nanoparticles are invisible even to the best optical microscope, and  in our experience have no discernible effect on the appearance (including colour and clarity), weight, value or properties of the emerald.

The carrier liquid used for transporting the nanoparticles into the fissures is ethanol, i.e. a standard alcohol that evaporates completely within a few minutes, leaving no traces whatsoever.                  

What about stones that have no fissures?

Stones that are completely free of any fissures might not be suitable for the emerald paternity test, as all particles might get removed during the cutting and cleaning process. Based on our current experiences with the technology, the few emeralds that are loupe clean still feature sufficient fissures of submicroscopic dimensions for nanoparticles to penetrate into them and adhere to their walls, enabling a later paternity test. The Emerald Paternity Test is the first technology of its kind, developed by the Gübelin Gem Lab that allows the tagging of emeralds. We are currently working on developing similar technologies for other coloured gemstones, such as rubies.

How will the information be read out?

The particles in the fissures are removed from the walls of the fissures, using a proprietary buffer solution. The retrieved DNA fragments are analysed using quantitative PCR (qPCR), a standard method applied for reading DNA. The analysed DNA is then decoded to determine the client specific information, such as the identity of the owner, the mining location, the mining period etc. The Gübelin Gem Lab is the custodian of the information encrypted into the DNA, and the sole party in charge of decoding this information.

How does it work?

Emeralds can be submitted to the Gübelin Gem Lab in Switzerland, Hong Kong or New York for performing the Emerald Paternity Test, i.e. for retrieving and analyzing the nanoparticles. For the time being, the analysis can be done at the Gübelin Gem Lab only. We foresee to contract a few other analytical laboratories that get entrusted with the extraction of the nanoparticles. The decoding of the information stored in the nanoparticles remains exclusively with the Gübelin Gem Lab.

How secure is the technology against counterfeiting?

In principle, reproducing a known DNA sequence is not a difficult task. So how can we assure that the information in the DNA-based nanolabels is not copied, reproduced and misused on emeralds other than the ones the genuine nanolabels are made for? First, the intellectual property of the nanoparticles and the application for emeralds is protected by different international patents, making a possible unauthorized application illegal. Better protection arises from the technological challenges a counterfeiter would have to overcome. The highest level of security stems from the fact that the technology is based on a key-lock system, meaning that reading the DNA sequence is only possible with a key specific for that sequence. That information is made inaccessible, kept under careful custody in bank vault. Hence, we feel that the Emerald Paternity Test technology is fairly secure against counterfeiting.

How to make sure that the technology is only applied on the right stones?

The nanolabels used in the Emerald Paternity Test contain information specific to a mine, a mining company and a mining period. These nanolabels must only be applied on the correct gemstones. We feel a strong obligation to minimize the risk that a specific type of nanoparticles is applied on emeralds other than the ones they are built for. Hence, no direct access to the technology is granted to the miner. Instead, the application of the tracer technology in the mine is handled exclusively by UL, an independent, professional auditor. This global company acts as a neutral custodian, and is entrusted with the handling of the technology at the mine, reducing the risk of uncontrolled applications of the technology.