Jadeite jade is a very porous stone. It comprises of very minute granules of monoclinic crystals inter-locked against each other. This creates a lot of ‘spaces’ and ‘pores’ in between the crystals whereby organic compounds can be force injected into these capillary crevices. Hence, jade is an extremely good stone for enhancement. (Read here for Internal Structure of Jade)
Enhancement and Treatment
A natural vivid color piece of jadeite jade with excellent translucency is a very rare piece of jade. Hence, jade ‘manufacturers’ often enhance a low grade jade piece to improve on its color, translucency and luster. The various forms of enhancement and treatment are:
- Dye Injection
- Polymer Impregnation
Waxing on the surface of a jade piece is not considered as an enhanced treatment. The internal part of the jade piece has not being altered in any way. Waxing is not permanent. After a while the wax will wear off or it looks dull when in contact with a hot medium. However, you can send it back to your jade dealer for re-waxing.
Dye injection has been used for many years. Usually spinach vegetable is used as it has a good vivid green and it is easily available. The pores of the jade pieces are preliminary washed in mild acid or plum juice to remove some of its surface impurities. Then it is pre-heated using a basin of hot water to open up the pores. The jade piece is then removed and soaked into vegetable dyes for about a few weeks.
On removing the jade piece, it is dipped in wax to seal off the pores. Using leather or sheep skin, the jade is polished until it is lustrous. This is not a common practice anymore as the dye leaks out easily. For some unscrupulous jade dealers who wanted a quick profit or to fleece tourists this practice is still prevalent in some remote part of Burma or China.
Polymer Impregnation is a more permanent method of treating a jade piece whereby polymer is force-injected under pressure into the capillary veins of the jade. Polymers with Refractive Index closed to Jadeite Jade is used (RI 1.66, read here). Occasionally, Opticon (with RI 1.54) is used.
The method of impregnating polymer is almost the same except that higher technology is used and it is done on a mass basis. Once polymer is impregnated into a jade piece the jade will have a very good luster and translucency. Polymer impregnation came into practice in Hong Kong in the late 70s.
Jadeite Jade which has NOT been treated is known as Natural Type A Jadeite Jade in the trade.
Polymer impregnated jade is known as Type B, Jadeite Jade, while jadeite jade which has been dyed is known as Type C Jadeite Jade.
By international standards, waving is not considered as an enhancement and jadeite jade which has been waxed but not dye injected or polymer impregnated is still considered as Type A Jadeite Jade.
The next post will discuss Type A, B & C Jadeite Jade.