Jade appraisal
One of the annoying problems in jade appraisal is the practice of dyeing weak-colored or off-colored jadeite to simulate the best-quality green stones. Sometimes the dyeing is obvious. Cheaper dyes will fade in sunlight in a few days. Under magnification the dye often looks like thin, threadlike lines of color where it is trapped between jade grains but does not penetrate the grains themselves. There are dyeing processes more difficult to detect, and some so clever as to require laboratory detection. Fortunately, these pieces are not so common and are usually limited to smaller carvings. Then, too, the collector is protected somewhat in the United States by rulings of the Federal Trade Commission that such material be labeled “dyed jade.”
For the buyer of jade carvings, there remains an important problem: determining the authenticity of age. Richard Gump, long familiar with the merchandising of jade carvings, gives several guidelines for this in his book on jade. Among his suggestions is this: “The style or design of an object would, generally speaking, indicate the period. Check the exact detail of design. If it is a Han vessel with a Ming or Sung design, you know something is wrong. The material used is a good indicator. If the piece is said to be pre-17 84 and of jadeite, look out. If it is labeled Ch’ien Lung and of distinctive spinach-green Russian jade, which came onto the market in 1920, you would again have due cause for suspicion.” The general trend of these remarks indicates the complexity of authenticating a jade carving and the long and detailed experience necessary for this kind of detective work.
Once a working knowledge of jade characteristics is acquired, another pressing question arises: what are the sources of all the rough material worked by so many different cultures in such great quantities? Until recent times it was actually believed by many scholars that all the jades of ancient Middle America came from China. They certainly couldn’t have come from there, for, astounding as it seems, jade was never found in China proper. All the works of four thousand years of Chinese jade carving were executed in imported stone. There has been much speculation that the earliest carvings were done in native stone and that when these deposits ran out a thriving import trade in rough jade from other sources was begun. Check also round diamond earrings.
Tags: diamonds, gems, jade, jewelry