Expert advice on watches and jewellery
Jade has been revered in Chinese culture for thousands of years. It was used for tools, ornaments, jewellery, and weapons in ancient China. Jade is the generic term for nephrite (silicates of calcium and magnesium) or jadeite (made of sodium and aluminium). Nephrite is mostly used in carvings and sculptures, whereas jadeite of gem quality is used in jewellery.
The best quality jadeite comes from Burma, although it is also found in Japan, Central America, and California.
Advanced mining techniques mean more mines have opened in recent years, making jadeite more readily available.
Things to look for in jadeite:
Jadeite comes in lavender, white, and black, but green is the most sought-after colour. Deep emerald green, also known as imperial jade, is most precious. Valuable green and lavender jadeite should look intense even from afar. Whichever you choose, the colour should be vibrant, rich and
even, and free of blue or brown veins, inclusions, and spots. White inclusions are less noticeable
than black ones - but both can substantially affect the piece's value. Good quality jadeite should have no inclusions visible to the naked eye.
This refers to the transparency and texture of the jade. Look for jadeite with a clear and silky texture, ideally with minimal irregularities. Good quality jadeite should look glassy.
Jadeite is usually cut into cabochons, beads or bangles. A cabochon has a smooth, dome-shaped top and flat bottom. Examine the contour of the dome to check it is smoothly curved and polished, making sure its length-to-width proportions are balanced. A well-cut cabochon should have no visible flaws.
Beads are usually made into necklaces, which means consistency in colour, texture, and shape are important when determining the overall quality. Bangles and saddle rings are the most traditional forms of jewellery and are especially valuable as they are carved from a single piece.
Trends and tips
Traditionally, dark emerald green jadeite known as lao keng (or
'old mine' jadeite) was the most popular. However, in recent years buyers prefer a more vivid green variety, says Quek Chin Yeow, head of jewellery at Sotheby's China and Southeast Asia. Quek says that white jadeite, commonly known as icy-jade - widely used
in carvings and sculptures - has become more popular, along with colours such as lavender and black. Having said that, quality emerald green jadeite remains the most valuable. Jadeite should not be treated in any way, apart from cutting and polishing. How can you tell if a piece has been bleached to remove impurities, or if it has been artificially dyed? Quek says it is difficult to detect with an untrained eye, but
if you have a microscope or spectroscope at home, examine the jadeite to check for
colour concentrates in the
veins. Unfortunately, detecting bleaching requires more sophisticated techniques than this.
If you are unsure of the jadeite on hand, take it to a professional jade and stone laboratory to be examined. Here it will be categorised into A, B, and C grades: A is 100 per cent natural; B has been treated to remove blemishes and impurities; and C has been dyed.
Buying from reputable dealers and auction houses are reassurances of quality. Many jadeite jewellery pieces sold at auction are accompanied by certificates ensuring they are natural and untreated. If the jadeite hasn't been examined, request that the jeweller arrange that for you, and don't purchase from those who show reluctance to give you a proper certificate. Buying at reputable jewellers
is fine as
long as the jadeite has been examined at a professional laboratory, such as the Hong Kong Jade and Stone Laboratory.
22/F Alexandra House, 18 Chater Rd, Central; tel: 2521 5396.
An auction of jewellery, including spectacular jadeite pieces, will
be held on June 1, Hong Kong Convention and Exhibition Centre, Wan Chai.
BL6A, The Peninsula, Salisbury Rd, Tsim Sha Tsui; tel: 2368 1328.
Qeelin's Tien Di collection features jadeite in black, white, brown, and green.
Suites 3101-3106, One Pacific Place, 88 Queensway, Admiralty; tel: 2822 8119.