There are a number of websites that describe Type B, Type C and Type B+C Jadeite Jade.
Seems that these jade websites are quick to jump on the bandwagon without really doing any research on the subject matter.
Read this post Type C – Much Ado About Nothing for more information on Type C Jadeite Jade.
One must note that the description of Type A and Type B is internationally accepted as auctions on jade by major Auction House of Christie’s and Sotheby are always accompanied by Jade Certificates done by reputable Gemological Labs in Hong Kong.
But Type C Jadeite Jade is just inferred based on the color streaks within the jade piece against the background of whitish polymer. If a gemlab detects a Type B Jadeite Jade, nobody is going to pay them to determine whether the green color streaks within the jade is made of color dyes or the color is another type of organic matter different from the polymer used to impregnate the jade.
The following passages appear in Wikipedia on Type B, C and Type B+ C Jade :
- “ Type B treatment involves exposing a promising but stained piece of jadeite to chemical bleaches and/or acids and impregnating it with a clear polymer resin. This results in a significant improvement of transparency and color of the material. Currently, infrared spectroscopy is the most accurate test for the detection of polymer in jadeite.
- Type C jade has been artificially stained or dyed. The effects are somewhat uncontrollable and may result in a dull brown. In any case, translucency is usually lost.
- B+C jade is a combination of B and C: it has been both artificially dyed AND impregnated. “
Except for the statement of Type B, the other 2 statements are conjectures.
The following specimen jade bangle is examined under a 120x gem microscope and different areas on the jade bangle are being scanned using an Fournier Transform InfraRed (FTIR) equipment.
The following are observations:
1) The green streaks appear on the peripheral of the bangle, perhaps a few microns away from the surface.
2) There are no green streaks in the interior of the bangle. One can infer from here that the green streaks are dyes stained into the jade piece.
A few areas of the bangle are scanned. The subsequent charts are the same. Note that on the Y-axis the percentage of Transmission is shown while on the X-axis the wave-number is shown. The absorption peak of 3037 wave-number corresponds to the polymer group of Alkenes.
Hence, whether the area of green streaks or the whitish area are scanned the charts remain the same indicating the fingerprint of the same polymer functional group.
So be wary of jade sellers telling you about Type C and Type B+C Jadeite Jade. They are not lying to you, but they are not in the know. I shall put up a post later on what sales talk sellers pitch to you on jade.
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