Guest article by Daniel Nyfeler, PhD – Managing Director, Gübelin Gem Lab Ltd. & Provenance Proof Ltd.
For decades, the diamond industry has relied on trust. While consumers appreciated the beauty and rarity of diamonds, relatively little information was available about where individual stones originated, how they travelled through the supply chain, or whether sustainability claims could be independently verified. The complexity of global supply chains, combined with extensive sorting, mixing and manufacturing processes, meant that precise provenance was often difficult or even impossible to demonstrate. And some industry players might not even have been much interested in providing this information to consumers.
Today, expectations have changed fundamentally. Consumers, luxury brands and regulators increasingly demand greater transparency throughout the jewellery supply chain. Questions that were once rarely asked have become standard: Where did this diamond originate? Who handled it? Can its provenance actually be verified?
Equally important, the industry is witnessing a shift from self-declared claims towards independent verification. Rather than relying solely on supplier statements or documentation, stakeholders increasingly seek objective evidence that the information associated with a diamond genuinely belongs to that specific stone.
Digital traceability has transformed the industry
Over the past decade, numerous digital traceability platforms have emerged. Blockchain solutions, cloud-based databases and digital passports have significantly improved the recording of information throughout the value chain. They enable stakeholders to document ownership, manufacturing steps, logistics and sustainability data in a secure and transparent manner.
These systems have brought considerable progress to the industry. They improve record keeping, facilitate compliance and allow brands to tell richer stories about their products.
However, all digital systems share one fundamental challenge: they record information about a diamond, but not the diamond itself. If a stone is accidentally mixed, intentionally substituted or exchanged during manufacturing or logistics, the digital record may remain intact while no longer corresponding to the physical material. The digital identity becomes separated from the physical object, a challenge sometimes referred to as the “physical-digital gap.” This limitation is particularly relevant in complex manufacturing environments where thousands of diamonds, especially melee diamonds, are processed simultaneously.
Connecting the physical stone with its digital identity
To bridge this gap, Provenance Proof combines digital documentation with physical tracer technology. The concept is straightforward: instead of identifying only the associated information, the diamond itself receives an invisible physical identifier. This creates a direct connection between the physical stone and its digital record. The physical tracers consist of submicroscopically small silica particles containing synthetic DNA markers. With about 100 nanometer in size, they are invisible to the naked eye or any optical microscope, do not alter the appearance of the diamond, and are designed to withstand the standard processes encountered throughout the jewellery supply chain. Verification is performed by retrieving a small sample from the diamond or jewellery item, by either immersion or a simple swab test, and analysing it using quantitative PCR (qPCR), a well-established laboratory method capable of detecting the unique DNA signature. Successful verification confirms the presence of the retrieved physical marker and enables the issuance of a verification report. Unlike conventional identification methods that rely on surface characteristics or imaging, the physical marker remains associated with the material itself.
The advantages of physical tracers become especially apparent for melee diamonds. Individual scanning, mapping or high-resolution imaging can be practical for larger stones but often becomes technically or economically challenging when dealing with thousands of small diamonds. Since melee diamonds are routinely mixed during sorting, polishing and jewellery manufacturing, maintaining their individual provenance presents a significant challenge. Physical tracers address this issue by allowing entire batches of diamonds to be marked efficiently. The marker remains with each diamond throughout subsequent processing, enabling later verification even after the stones have been mounted into jewellery. This provides brands with an additional layer of confidence regarding supplier identity and declared provenance without requiring every individual stone to undergo complex imaging or repeated manual identification.
From coloured gemstones to diamonds
Although the application of physical tracers to diamonds is relatively recent, the underlying technology is well established. Physical tracers have been used commercially for almost a decade within the coloured gemstone sector, particularly for emeralds. Since 2017, large-scale applications directly at the mine, on the rough emerald crystals, have demonstrated that the technology can be integrated into existing supply chains without affecting cutting, polishing, cleaning or common treatment processes.
The long-term commercial use of the technology has provided valuable operational experience regarding scalability, durability and routine verification procedures. Its successful adoption in coloured gemstones has created the foundation for its extension into the diamond industry. Over the past year, physical tracer technology has begun to gain traction within the diamond sector. One notable example is KGK Suisse, which has implemented Provenance Proof physical tracers for selected melee diamond collections. Following cutting and polishing, the diamonds receive the invisible physical markers before entering the downstream supply chain. The associated supply chain information is simultaneously recorded on the Provenance Proof Blockchain, creating a digital logbook that accompanies the diamonds through manufacturing, distribution and retail. The combination of physical verification and digital documentation allows downstream users, including jewellery and watch manufacturers, to verify both the authenticity of the supplier relationship and the declared provenance of the diamonds used in their products.
This integrated approach combines the strengths of both technologies. The blockchain provides secure, immutable documentation of supply chain events, while the physical tracer maintains the connection between the digital record and the actual material.
Towards auditable provenance
Traceability is increasingly becoming a prerequisite for responsible sourcing, regulatory compliance and consumer confidence.
Digital systems alone have greatly improved transparency, but they carry the risk that physical materials become separated from their associated records. Physical tracers address this remaining challenge by enabling the material itself to become part of the verification process. For the first time, third parties can independently verify not only the recorded information but also that the information belongs to a specific batch of diamonds being examined. As the industry continues to move from narrative-based sustainability claims towards evidence-based verification, technologies that combine secure digital records with physical authentication are likely to play an increasingly important role.
For manufacturers, brands and retailers, particularly those working with melee diamonds, this represents a practical pathway towards more robust and trustworthy provenance verification. Ultimately, verifiable traceability is no longer simply about documenting where a diamond has been. It is about demonstrating, with independent evidence, that the diamond itself truly is the one described by its history.
How Physical DNA Tracers Work
Unlike conventional traceability systems that record information about a diamond, physical DNA tracers are applied directly to the diamond itself, creating a permanent link between the physical material and its digital identity.
Application
Invisible tracer particles, consisting of synthetic DNA encapsulated in submicroscopically small silica particles, are applied to the diamonds. The process does not alter the appearance, weight or gemmological properties of the stones. Depending on the supply chain, tracers can be applied to rough diamonds, polished diamonds or even finished jewellery.
Verification
At any stage of the supply chain, the physical tracer can be recovered using a simple swab or immersion procedure. The unique DNA signature is then detected by quantitative PCR (qPCR), a widely established laboratory technique. Successful detection confirms that the physical diamond carries the assigned tracer and allows independent verification of its documented provenance.
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