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What’s in a name? The use of historical terminology to describe colour

These terms not only infer the finest colour in their respective class, but also the locale where they were found. Colour and origin matter today, especially in the high-end. Reputable labs are necessary; they have sophisticated equipment that not only identifies the material as natural or synthetic, but if treated, the kind of treatment and to what extent. A good friend in the auction business told me, “Auction houses must have grading reports from the major labs that include AGL, GIA, Gübelin, and SSEF. We live and breathe through the labs due to buyer and seller demand. We are constantly at their mercy for time and grading results. In order to get top-dollar, as you know, it’s of the utmost importance.”

To calm fears, these labs aren’t assigning colours willy-nilly. I’m told that at AGL, only very fine stones merit ancillary reports. Further, only a select few will be likened to these historical and coveted terms within these reports. The problem is, opportunistic fringe labs don’t have an issue calling a cough drop ‘pigeon’s blood,’ and when the consumer sees the term on a report from a reputable lab, a sliver of legitimacy creeps in.

What do we, as valuers, do with these reports? Most labs use their own grading systems, as opposed to the ones we might use. My suggestion is to colour-grade the stone as we would any other using repeatable methods, which aren’t really ‘systems,’ but attempts to describe the appearance of faceted coloured gemstones based on the Munsell Color System. This is a good system: gem-identification labs (who have no bias as to the value of a gemstone) provide the facts, while accredited qualified valuers (also unbiased) use repeatable colour-grading codes that we can further decipher into layman’s terms that help the readers and users of our reports better visualize their stone.

This is an ongoing discussion that is sure to change from year to year. Personally, I feel less fanciful wording would be better for the consumer, but more descriptive terms, if used with care, might light a crimson flame for coloured gemstones.

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Carole C. RichbourgCarole C. Richbourg is an independent gemmologist/appraiser in Northern California and has been appraising full time since 1999. She is an accredited senior appraiser, master gemmologist, and a fellow of the Gemmological Association of Great Britain. Richbourg is co-instructor for the American Society of Appraiser’s (ASA’s) GJ-202 appraisal report writing for insurance coverage class. She may be contacted via e-mail at

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