Oriental Emerald — An Obsolete Trade Name for Green Sapphire
Oriental Emerald — An Obsolete Trade Name for Green Sapphire
A nineteenth-century misnomer for corundum, discouraged under modern disclosure
Oriental emerald is an obsolete trade term for green sapphire — corundum coloured in the green range, typically by iron — used historically to distinguish gem-quality green corundum from beryl emerald and to imply an Asian origin. The term is a misnomer in the technical sense and is discouraged under modern disclosure standards. Both the Gemological Institute of America and the American Gem Trade Association identify green corundum as green sapphire, with the colour modifier preceding the species name. The compound term oriental emerald should not be used in trade practice.
Origin of the term
The qualifier oriental entered nineteenth-century gem terminology to denote stones thought to be of superior quality or of Asian provenance, often coupled with a familiar western variety name to communicate colour. Oriental emerald for green sapphire, oriental amethyst for purple sapphire, oriental topaz for yellow sapphire, and oriental aquamarine for blue-green sapphire all follow the same nineteenth-century pattern. The vocabulary served a market that wanted to convey colour through familiar names, but it conveyed no useful information about the actual species and obscured the simpler fact that the stone was sapphire.
Why the term is discouraged
Emerald is the green variety of beryl, coloured by chromium and sometimes vanadium, with hardness 7.5 to 8 and refractive index near 1.565 to 1.602. Sapphire is corundum (Al2O3), hardness 9, refractive index 1.760 to 1.778. Calling a green sapphire an emerald, even with the oriental qualifier, misrepresents species, durability, and price tier. A buyer who is told oriental emerald may reasonably believe the stone is beryl, and the implied price comparison to fine emerald is misleading.
Laboratory practice and disclosure standards identify green corundum as green sapphire and document treatment where applicable. The term oriental emerald has no place in current laboratory documents or modern trade descriptions and survives only in older catalogues and museum labels for nineteenth-century pieces.
Practical guidance
If a stone is offered as oriental emerald, the buyer should ask for the species identification. If the stone is corundum, it should be sold as green sapphire and may be accompanied by a laboratory report. If the stone is beryl, the term emerald applies without the qualifier. Older auction catalogues and antique-jewellery descriptions sometimes reproduce the historical term for reference; in such cases the species identification of the stone should be verified by gemmological examination rather than read off the catalogue label.
See also sapphire, oriental amethyst, oriental topaz, oriental aquamarine, emerald.