Sonja McLahlan (UK)
In the fifth and final of my articles on jade, I will look at some of the recognised methods of identifying processed jade items and raw jade found in uncut boulders. I will also discuss the idea of jade as a valuable trade commodity throughout the world, along with the important contribution it makes to the local and national economies of many Asian countries. At the end of the article, I will discuss the modern jadeite and nephrite-processing methods and the locations of major jade cutting centres in Asia.
Identifying jade: real or fake?
In the field, New Zealand collectors test river boulders by hand and considerable experience is needed to correctly identify jade pieces. Samples of real jade do not sparkle or glitter when chipped and cannot be scratched with a knife. Jade also has a smooth, waxy or greasy look and feel, and is heavier than expected when lifted.
Collectors should be wary of fakes when searching in any marketplace. Unfortunately, cheap jade imitations are commonly found on sale in markets, the most common being ‘serpentine jade’, a form of green serpentine that is a combination of several minerals and is much softer than real jade. Occasionally, colour intensified nephrite can be found being sold as jadeite. Onyx marble, which has been dyed green, can also be found being represented as jade.
The value of jade is greatly enhanced if it has the following complete set of desirable characteristics: an intense, even colour; honey-like translucency; a watery lustre; a smooth finish; an even texture; and a vivid root-like structure.
Jadeite tends to command higher prices at market due to its vivid green colour range and finer translucency. Its greater value leads to it being used more extensively in jewellery making.
Jade items are increasingly popular today among collectors, with the main markets being found in Taiwan and China. The Chienkuo jade market in Taipei was established over ten years ago and hosts over 900 stalls. The items on display here are the final products of jade artists from Taiwan, Hong Kong, Mainland China and Indochina. In China, the Hetian Jade Trading Centre in Urumqi, Xinjiang’s capital, opened in 2005. The centrefocuses mainly on the sales of local Hetian jade stone that is found in white, green, blue-green, black, yellow and yellow-green tones. The most expensive white stone, or ‘mutton fat’ jade, is worth HK$97,500 per kilo (August 2006) which is approximately £6,200 per kilo at today’s exchange rate.
In Myanmar, the ‘Gems, Jade and Pearls Emporium’ has been staging an annual show since 1964, earning the country over US$600million. In 2006, 1,220 gem merchants from 12 countries attended the event. Blocks of jade of all sizes are available for sale through a tender and auction system, with a recent jade block example weighing in at 1,188kg. However, buyers need to be wary, as the rough, uncut jade blocks or jade slices are difficult to value when on display. These items have usually undergone only minimal grinding to reveal the quality of the jade within. Any speckled or streaked jade found at these auctions is judged to be much less desirable and, therefore, less valuable than the famous green jade. In addition, Christie’s auctioneers organise jade auctions in Hong Kong, and jade markets take place in both Rangoon and Hong Kong.
The main jade processing and cutting centres are found in Canton, Beijing and Hong Kong. The raw materials are processed using carborundum and diamond powder. Stone files are used for detail, and smooth polishing is achieved with fine grits and eventually oil to give the mirror polished finish. Since jade is not transparent, but has a fine lustre, it is most suited to a form of cabochon (a gem that has been polished but not faceted) to be set in rings and pendants. Traditionally, jade is processed into slender carved figures, set into filigree jewellery items or carved into ornate thin-walled vessels. During processing, the subtle differences between nephrite and jadeite become clear: polished nephrite has a surface with a resinous lustre, whereas polished jadeite has a glassy lustre that seems to shine like a mirror.
This article concludes my discussions on jadeite and nephrite. I have found jade to be a fascinating subject and more detailed information on jade world geography, history, symbolism, uses, trade and other aspects of jade can be found on the websites listed below.