The Swiss-based Gübelin Gem Lab and Swiss Gemmological Institute SSEF, recognised as the leading laboratories for coloured gemstone testing, have agreed to harmonise their standards for the colour terms ‘pigeon blood red’ and ‘royal blue’ on 4 November 2015, aiming to standardise the usage of these terms for the benefit of the international gemstone industry.
The colour terms ‘pigeon blood red’ and ‘royal blue’ have been used for centuries by the trade to describe, respectively, only the finest quality rubies and sapphires, which aside from their distinct colours, invariably are stones of superior quality, and hence are among the most coveted gemstones. However, referring to fine quality stones of specific hues of saturated red and blue, there has been no definite agreement on the precise colours and quality criteria that correspond to the two terms.
Initially, SSEF and Gübelin independentlydeveloped their own strict criteria for these colour terms. With the intention to bring clarity to the industry, the two labs mutually compared their criteria, and found them to largely coincide. Based on colour and quality, a few minor changes were agreed upon to further harmonise the standards the two labs apply.
“By applying these harmonised standards, it is the aim of SSEF and Gübelin Gem Lab to provide the trade with unified and consistent guidelines for the use of these historically significant terms,” said Michael Krzemnicki, director of SSEF.
“Clearly, such stringent sets of criteria imply that only a very small percentage of rubies and sapphires qualify,” stated Daniel Nyfeler, managing director of the Gübelin Gem Lab. “This is in line with the experience and belief of both Gübelin and SSEF that historically only exceptional rubies and sapphires were attributed these quality terms.”
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