We’ve been working on an insurance appraisal for this wonderful platinum necklace with diamonds and jadeite from the 1920′s and realized the piece has a lot to teach about grading and valuing jade.
Jade is not well understood by many folks. If I told you that jade can be one of the most expensive of all gemstones, you would probably be surprised– some pieces sell for well into six figures. Even jewelers who really know their way around the faceted stones have a hard time with jade, especially when we don’t often see really good jade like this necklace.
Jade is actually two different minerals. Nephrite is the one we see most often in ancient chinese carvings and artifacts as well as inexpensive jewelry items, while jadeite, discovered in Burma (Myanmar) in the early 1800′s, is the more beautiful and valuable type used in fine jewelry.
The more vivid and semi-transparent colors of jadeite, especially the emerald green known as “Imperial” or “Kingfisher” are highly sought after, especially in Asia and can sell for truly astounding prices. When we grade jade as a gemstone, we are usually talking about jadeite.
We grade quality in diamonds according to the 4 C’s. When we grade quality in jadeite, besides grading the color as we do in other colored gemstones, we evaluate what I call “the 3 T’s”– translucence, texture, and tone.
Our Art Deco necklace is set with jadeite stones that blend well for color, but we can see different examples of the 3 T’s.
The carving of the gourd and cat is the highest quality in the necklace. While the tone of the green could be described as medium with strong saturation, it also exhibits a nice degree of translucence and the material has a very even texture so that we don’t really see individual particles within the jade, just a really nice “smooth” appearance. Even without the backlighting, the jade has a “glow” where the rich color seems to come from within rather than just from the surface.
The oval cabochon in the center of the necklace has a similar tone of green, but while the texture is even, you can see a slight graininess and the translucence is not at the same level, so the color is not as saturated.
The round cabs in the necklace have a similar hue of green that blends well with the two center stones, but the tone is variable with light and dark areas, the texture is somewhat grainy, and the translucence is less.
The carved jadeite is beginning to approach what we might call Imperial- the hue and tone of green and the even texture are about right, but Imperial jadeite is semi-tranparent and the color saturation is more vivid. Overall, the necklace is a beautiful piece typifying the Art Deco design ethic and a wonderful example of the range and subtlety of jadeite.
james l. sweaney cga fga. gg
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