GemResearch Swisslab AG — universally abbreviated to GRS — is a gemological laboratory founded in 1996 by Dr Adolf Peretti, a Swiss gemmologist and researcher whose career had previously included fieldwork in gem-producing regions of Asia and Africa. Headquartered in Lucerne, Switzerland, with a principal operational branch in Bangkok, GRS has become one of the most influential independent laboratories specialising in coloured gemstones. It is particularly distinguished for introducing and defending proprietary colour-quality designations — most notably pigeon's blood for ruby and royal blue for sapphire — that have been absorbed into the vocabulary of the international gem trade and, critically, into the price structures of major auction houses.

Founding and institutional character

Dr Peretti established GRS at a moment when the coloured-stone trade was grappling with the absence of standardised quality language. Unlike the diamond sector, which had long operated under GIA's Four Cs framework, the ruby, sapphire, and emerald markets relied on dealer idiom that varied by origin, language, and tradition. Peretti's ambition was to apply rigorous spectroscopic and inclusion-based analysis to coloured stones and to anchor qualitative descriptors — especially colour grades — to measurable, reproducible criteria. The Bangkok branch is strategically placed within the world's largest coloured-stone trading hub, giving GRS direct access to the Burmese, Thai, Sri Lankan, and East African material that flows through the city's gem quarter.

Proprietary colour designations

GRS's most commercially consequential contribution has been its formalisation of traditional trade colour terms into laboratory-certified grades. The three principal designations are:

• Pigeon's blood — applied to rubies of a specific red hue with a faint blue secondary tone, high saturation, and strong fluorescence under ultraviolet light. The term derives from a Burmese trading tradition, but GRS was among the first laboratories to define it against spectroscopic and colorimetric benchmarks, making it certifiable rather than merely subjective.
• Royal blue — applied to blue sapphires exhibiting a saturated, velvety blue with a violet secondary component, most classically associated with Kashmiri and Burmese material. The designation distinguishes stones of the highest colour quality from those graded simply as blue.
• Vivid green — applied to emeralds and, in some contexts, to tsavorite garnets and other green stones meeting defined saturation and hue parameters.

These designations appear as supplementary colour-quality statements on GRS reports and carry measurable market premiums. At major auction houses — Christie's, Sotheby's, and Bonhams among them — a GRS certificate noting pigeon's blood colour or royal blue colour is routinely cited in lot descriptions and is widely understood to support higher reserve prices. The influence of these grades is especially pronounced in the Hong Kong, Singapore, and mainland Chinese markets, where GRS reports enjoy particular authority.

Analytical methodology

GRS employs a suite of analytical techniques consistent with contemporary gemmological practice at the highest level. These include:

• Advanced optical microscopy for inclusion characterisation and identification of growth structures indicative of geographic origin.
• Ultraviolet-visible-near-infrared (UV-Vis-NIR) spectroscopy for chromophore identification and the detection of treatments such as beryllium diffusion in sapphire or glass filling in ruby.
• Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for trace-element fingerprinting, which underpins geographic origin determinations.
• Raman spectroscopy and infrared (FTIR) spectroscopy for species confirmation and the detection of polymer, oil, or resin fillings in emeralds and rubies.
• Photoluminescence spectroscopy for the detection of heat treatment in corundum, including the identification of residual silk and the condition of growth planes.

The laboratory maintains an extensive reference collection of gemstones of documented provenance, which forms the comparative basis for origin determinations. This collection, assembled over decades of fieldwork and acquisition, is a material asset that distinguishes GRS from laboratories relying solely on published spectral databases.

Geographic origin determination

Origin determination — establishing whether a ruby came from Mogok or Mong Hsu, whether a sapphire is Kashmiri, Burmese, or Sri Lankan — is among the most commercially sensitive services any coloured-stone laboratory provides. GRS has built a strong reputation in this area, particularly for Burmese ruby and Kashmir sapphire, the two origin designations that command the greatest premiums in the current market. The laboratory's Bangkok location facilitates access to material from Myanmar, and its long engagement with Asian gem-producing regions has informed a reference database of considerable depth. GRS origin reports are accepted by the major international auction houses as authoritative, though, as with all origin determinations, the conclusions represent expert opinion based on the balance of available evidence rather than absolute proof.

Publications and research

GRS publishes a peer-reviewed journal, Contributions to Gemology, which serves as the primary vehicle for the laboratory's research output. The journal has carried articles on topics including new mineral inclusions in corundum, the spectroscopic signatures of beryllium-treated sapphires, the gemmology of Burmese spinel, and the characterisation of Paraíba-type tourmalines from various localities. Dr Peretti has also authored and co-authored articles in Gems & Gemology, the journal of the Gemological Institute of America, lending his findings additional reach within the international gemmological community. This commitment to publication distinguishes GRS from some of its competitors and situates it within an academic as well as commercial tradition.

Position in the laboratory landscape

The coloured-stone laboratory sector is served by a small number of institutions whose reports are accepted at the highest levels of the trade. GRS occupies a distinct position within this group. Where GIA (Gemological Institute of America) and Gübelin Gem Lab (Lucerne) are often regarded as the traditional benchmarks for Western markets and for diamond-adjacent fine jewellery, GRS has cultivated particular authority in Asian markets and among dealers and collectors focused on Burmese, Sri Lankan, and East African material. The three laboratories are not in competition in a simple sense; sophisticated buyers frequently seek reports from more than one institution, particularly for stones of significant value, and the concordance or divergence of conclusions between laboratories is itself a subject of trade discussion.

GRS reports are formatted to present origin determination, treatment status, and — where applicable — colour-quality designation on a single document accompanied by photographic documentation of the stone. The laboratory also issues GRS type designations for certain treatments, a classification system that has been adopted as reference language by segments of the trade.

Influence on market values

The practical consequence of GRS certification, particularly for colour-quality designations, is well documented in auction records. Burmese rubies accompanied by a GRS report citing pigeon's blood colour and no indications of heat treatment have achieved per-carat prices substantially above comparable stones lacking such certification. The same pattern holds for Kashmir sapphires graded royal blue. This premium reflects not only the laboratory's analytical credibility but also the role its colour language has played in creating a shared vocabulary between sellers and buyers across linguistic and cultural boundaries — a function that is, in its own way, as significant as the technical analysis itself.

Further reading

• Gems & Gemology — GIA's peer-reviewed journal, gia.edu
• Lotus Gemology — commentary on ruby colour grading, lotusgemology.com