Mr. Kay let us know that quality jadeite comes from numerous locations around the world. Burma having the finest jadeite, although some comes from Guatemala and Siberia—but the quality is different.
Burma jade is still a restricted export in the USA. On Nov. 16, 2012 the State and Treasury Departments lifted sanctions on a variety of products from Burma — but left ruby and jade off that list. So the removal of sanctions did not include the existing prohibitions and restrictions on the importation of jadeite and rubies mined or extracted from Burma, and on articles of jewelry containing them. Hopefully, 2013 will find the prohibitions on jade lifted by the USA to match the EU which removed all such sanctions and restrictions early in 2012.
Jadeite’s quality is first determined by color, then texture. Green is the most important color, while the rarest is lavender. Red, yellow and ice jade are growing most rapidly in value. A smooth, even texture is most desirable. Black (yes, black jadeite) and gray jadeite value is approximately that of commercial quality green jadeite.
The finest material is dedicated to cabochons. The ideal proportions for a cabochon are 1x2x3 (depth, width, length), and preferably a double cabochon as well. An orange rind texture is typical for jadeite jade polished, though cutters are now able to achieve a mirror polish using diamond dust.
Beads, bangles and drops have a great waste factor, so their value goes up faster (beads typically have a 50% waste factor). Smooth trumps carved material in value in jadeite, and cracked cabochons have less value because they don’t sell.
‘A’ Jade: Natural, untreated jadeite jade. Only beeswax is used to fill the stone’s microscopic surface pores – as has been done for centuries
‘B’ Jade: Acid-bleached, polymer-impregnated jadeite jade. Ultimately, even experts
cannot be certain by eye alone whether or not a piece is ‘A’ or ‘B’ jade. Polymers leave
a tell-tale trace in the infra-red spectrum. A machine called an infra-red spectrometer
can detect this trace quite clearly. Mason-Kay is currently the only commercial firm in
the United States equipped with its own infra-red spectrometer since 1995.
‘C’ Jade: Acid-bleached, polymer-impregnated, dyed jadeite jade – the dyed form of ‘B’ jade
Those of you who missed Don Kay’s lecture missed a wealth of information as well as gorgeous slides and a catalog on jadeite.
We should all keep in mind that Mason Kay is not only generous in sharing their knowledge on jadeite, but they are also purveyors of untreated jadeite and their lab is indispensable for testing jadeite for treatment and providing appraisals.
In addition to a 50/50 Cash Raffle, two of Bobby Mann’s Ivory Identification – A Photographic Reference Guide were Raffled Off.
You can find Bobby’s first book on http://www.magcloud.com : Search for Ivory Identification.
You can find Bobby’s second book: Ivory Identification – A Photographic Companion at http://www.amazon.com : Search for Ivory Identification Companion.
Photos by Melanie Marts, GG
Meeting Notes Submitted by Charlie Marts