Because the right combinations of color, transparency, and texture can raise the value of jadeite to spectacular levels, many producers use treatments to improve jadeite’s appearance. Some of these treatments have been around for a very long time and are accepted as part of the traditional jadeite finishing process. Other treatments are much newer and have aroused a great deal of concern in the industry.
The trade groups jadeite into three basic types: Type A, Type B, and Type C.
Type A jadeite is natural jadeite that manufacturers dip into melted wax after cutting and polishing to improve its luster and to fill surface pits and fractures. To help the material absorb the wax and to prevent cracking, manufacturers boil the jadeite in water before dipping it. The wax fills the spaces between the microscopic crystals and gives the jadeite a smooth, bright look. This traditional treatment is extremely common, and it doesn’t affect value.
Type B jadeite is natural jadeite that’s subjected to a series of processes to improve its looks. Manufacturers of Type B jadeite soak the gem in hot hydrochloric or sulphuric acid for long periods. The acid bleaches out any undesirable brown or yellow oxidation stains. It also leaches sodium out of the jadeite, which alters its chemical composition. This compromises its durability, and it can become brittle. When it’s removed from the acid, the material looks dull and chalky. It also contains tiny voids. In order to improve luster, transparency, and color, manufacturers fill the voids by impregnating acid-treated jadeite under pressure with paraffin wax or clear polymer resin. This makes the jadeite more attractive and easier to sell. Some Type B jadeite is sold without treatment disclosure. This questionable practice creates turmoil in the jadeite market. But when people know they’re buying treated, Type B jadeite, they have realistic expectations about value and can negotiate a fair price. Type B jadeite also exists in older jewelry. The process has been around since at least the mid-1970s.
Type A jadeite —Natural jadeite enhanced only with a surface coating of wax.
Type B jadeite —Natural jadeite that’s bleached in acid to remove undesirable staining, then impregnated with wax or polymers.
Type C jadeite —Natural jadeite that’s dyed and often bleached and impregnated with wax or polymers.
Jadeite treatments are common, and it can be difficult to tell treated material from untreated.
Jadeite that contains iron inclusions can be heat-treated to produce orange and red hues. Jadeite heat treatment is stable and undetectable.
--Extracted from GIA - COLORED STONE- JADE
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