Dealers Warn Against Doctored Jade : Gems: Merchants have found a nearly undetectable way of making low-grade stones appear to be expensive jewels.

Jade is one of the most rare and revered stones in traditional Asian cultures, commanding up to $180,000 in San Gabriel Valley jewelry stores for a thin bangle of clear green.

But just as all that glitters is not gold, leaders of the local jade trade are warning the public to be skeptical of stones, even those beaming that most desirable shade of deep, translucent green.

Unscrupulous jade dealers in the Far East recently perfected a method of making lower quality jade look so much like its top quality counterpart that it takes a sophisticated and expensive machine test to tell them apart. The problem is so widespread that up to half of what’s being tested today in the United States is found to be adulterated, experts say.

This has special implications in the San Gabriel Valley, where a large and affluent Chinese community is at risk for fraud. A bracelet sold for $30,000 as grade A jade, for example, is worth only $2,000 if made of grade B jade. Dealers worry that the cheaper imitations masquerading as grade A, or imperial jade, could blow the bottom out of the high-end market.

“It has become a major problem for us,” said Hing Wa Lee, owner of the Hing Wa Lee Jewelry Store in the fashionable San Gabriel Square Shopping Center on Valley Boulevard.

Lee is president of the Jade & Gemstone Assn. of America, a group of 30 merchants who want to preserve the market for grade A jade and have launched a campaign to educate consumers about the differences via flyers printed in Chinese.

The counterfeiting method involves using acid to bleach out mineral impurities in lower quality jade. A high-pressure machine then injects a plastic polymer resin into the stone to conceal the tampering. A second way to enhance the jade’s color--and thus its value--is to shoot a marred stone full of plastic to make it look more translucent.

“The problem’s come over here now that we have more Chinese living here,” said David Lee, Hing Wa Lee’s son and partner.

The Lee flyer, which is distributed on bright yellow paper to shoppers and browsers who wander near the jewelry store, begins: “Please Beware of Purchasing ‘Fake’ Jades.” It says that a tampered-with stone loses its translucent look within three years and becomes worthless.

The flyer encourages prospective buyers to patronize only merchants with a trusted name and a permanent shop location, to inquire about the quality of the gem they are buying and to warn merchants that it is against the law to misrepresent impregnated stones as grade A jade. The flyer also recommends that buyers ask merchants to supply a certificate of authenticity from the Gemological Institute of America, an organization that authenticates precious stones.

“I heard one story about a guy who got into a (hot tub) wearing a clear green jade ring and when he got out, the color had become milky,” recalled David Lee, a third-generation jade merchant, explaining the pitfalls of buying impregnated jade.

The use of jade dates to at least 4000 BC. The stone, thought to have magic powers, was placed in the earth at planting time to bring good harvests and was buried with the dead to prevent the decomposition of bodies and assure passage to heaven.

Today in Hong Kong, more than 400 licensed jade dealers work in the city’s jade market, located in Kowloon. The giant auction house Sotheby’s has organized two auctions on jade carvings each year in Hong Kong since the 1980s. Dealers recall a 12-millimeter bracelet carved out of a single piece of jade that sold for $1 million.

“Here, nobody from a Western background cares about jade; it’s a very small market. But it’s a very important and traditional gem in China. That’s basically all they know,” says Emmanuel Fritsch, who heads the Gemological Institute’s research office.

The problem with adulterated jade became so severe in Hong Kong last year that the government passed a law saying dealers who knowingly misrepresent jade to customers can be jailed, Lee said.

In Japan, sales of jade fell by 50% in 1991 after the media reported that altered jade was going undetected, according to an article in Gems & Gemology, a trade publication.

While the counterfeiting is common knowledge among Asian dealers on both sides of the Pacific, many Caucasian dealers and gem experts here say they have heard no complaints and were unaware of it. “We have not had one call on this,” said a spokesman for the California Jewelers Assn. in Los Angeles.

What scares gem merchants most about the new high-tech fraud methods is that they cannot be detected by a naked eye or by traditional methods such as a light meter.

“Even a wholesaler who’s buying a bunch can’t always tell,” Fritsch said. “The jewelers, in good faith, sometimes don’t know what they have. These guys are basically merchants, they’re not gemologists, so this is new and disconcerting.”

The only sure test is to put the stones through infrared spectroscopy, a process that requires a machine that costs up to $100,000 and experienced technical staff both to obtain an accurate reading and to assess the results.

The price was worth it for the Hong Kong Stone and Jade Manufacturers Assn., which last year pooled its funds and bought one of the machines to test all jade they handled in Hong Kong, Fritsch said. Those who cannot afford the costs associated with buying a machine must go to a lab such as the Gemological Institute’s and pay about $200 for each piece tested.

The Gemological Institute of America, based in Santa Monica, says it receives at least two faxes a day from around the world from jade wholesalers and dealers who need help in determining whether they have grade A jade. Most of the jade handled by large auction houses is first authenticated through the Gemological Institute.

“Customers always ask me, ‘Is this real or is this altered?’ ” said Lee, who gets his jade from the Burmese jungle--the only place imperial jade is found--and cuts the stones in a Hong Kong factory, selling them to jade wholesalers throughout the world.

Fritsch says low-tech methods of altering jade have been around for decades but were usually discernible to trained dealers. One common method involved dying the jade with green plant extracts.

But in 1989, Fritsch saw his first plastic-impregnated jade. Today, he has documented five plastic polymers being used by dozens of jade traffickers in Hong Kong, Taiwan and Japan. Between one-fourth and one-half the jade that his lab is asked to test turns out to be impregnated, Fritsch says.