May/June 2001 Late Updates • Madagascan Ruby Floods Market • Merelani Mine Update • News from the ICA Congress in Sydney • Update to Situation at Laos Mine Stories from May/June 2001 • The Jade Age • New Find Yields Tanzanite Teaser • Tensions Boil Over at Merelani Mine • Gem ID: Jade Is Jade • Cuts: Drops of Light (Briolettes)

Three similar-looking stones. LEFT TO RIGHT: Nephrite jade, photo by Morgan Beard; chrysoprase from C.B. Gems, photo by Morgan Beard; Burmese jadeite, photo courtesy ICA.

. . . or is it?
More and more, top green chrysoprase is being passed off as jadeite.

By Donald Crowhurst, G.G.

I visited a jewelry store in the Chinatown section of one of Canada’s major cities and introduced myself to the pretty Chinese saleslady behind the counter. “I’m looking for information about jade; I see you have lots of it.”

With no customers in the shop, she gave me her full attention. “How can I help?”

“I’m wondering about the green lookalikes of jadeite jade, nephrite jade and chrysoprase.”
She looked puzzled. “I don’t know what you’re talking about. Jade is jade.”

Eventually my question became clear. She said, “We have Chinese jade and we don’t sell British Columbia jade. What was the other?”

“Chrysoprase,” I said, “This is the elite apple-green chalcedony that’s shipped to China from Australia.” She understood. She said, “Look there below you in the counter. That ring has Australian jade in it.”

Rough chrysoprase, photo by Morgan Beard.

There are only two kinds of authentic jade — jadeite jade and nephrite jade. The only thing the two minerals share is a name; they have different chemical compositions, different gemological properties, and even a different appearance.

Despite its association with China, most jadeite on the market actually comes from Myanmar (formerly Burma), and has only been imported to China since the late 18th century. The traditional jade of China was nephrite jade, although other green gems were called by the same name, yu.

Sometimes called “imperial” jade, jadeite is much more highly valued than nephrite, with the top-grade cabochons selling for $50,000 or more in Asia. True imperial color is rare, although jadeite is often dyed to improve its appearance.

A beautiful stone either carved or cut into cabochons, nephrite is found in great abundance in northern Canada, which is perhaps why the saleslady referred to it as “British Columbia” jade. “Australian jade” is a misnomer for natural chrysoprase, which, in its best quality, is identical to jadeite in appearance.

Gemology At A Glance
Gem	Composition	Mohs Hardness	Refractive Index	Specific Gravity	Chelsea filter color
Nephrite	Calcium magnesium iron silicate	6.0-6.5	1.600-1.627	2.90-3.02	Green
Jadeite	Sodium aluminum silicate	6.5-7.0	1.654-1.667	3.30-3.36	Green
Chrysoprase	Silicon oxide	6.0-7.0	1.53-1.54	2.58-2.64	Green

There have been a number of gems mistaken for — or passed off as — jade over the years, including serpentine, prehnite, adventurine quartz, and grossular garnet, also called “Transvaal jade.” Chrysoprase, however, has become the new rabbit in the park, somewhat like Australia’s rabbit population of years past: Its tribe increaseth and is exported mightily.

The world’s major source of chrysoprase is Marlborough, a tiny town in Queensland, Australia. Blink your eyes as you pass, and you’ll miss it. Now owned and operated by Gumigil Pty. Ltd., a Hong Kong-based company, the mine’s entire production of this prized green, semi-transparent to translucent chalcedony is shipped to Hong Kong for processing and world trade. Supplies from this lucrative, heavily-guarded mine are expected to continue for more than a quarter of this century, and perhaps as long as 40 years, at its current production level. In the year 1997-1998, the yield in rough stone exceeded $1 million in value.

Rings made of nephrite jade. Photo courtesy Jade West Corp.

Chrysoprase is a desirable gem in its own right and is gaining popularity among U.S. jewelry makers, but it can’t touch the value of fine jadeite.

Although there are differences, the three can also look enough alike to fool an unsuspecting buyer. Where do you begin to tell them apart?

Color is key.
Of jadeite, Richard T. Liddicoat Jr. writes that in its finest green color it bears a close resemblance to emerald. Along with the “glow” of live color, the “high intensity green,” a quality jadeite will be uniform in color, not blotchy; semitransparent in natural light; and inclusion free when held toward you, lit through from behind with a penlight or other bright light source.

The green of authentic chrysoprase, caused by traces of nickel, varies in shade from pale or yellowish green to Granny Smith apple green, its best color. At its best, it will be without flaws, inclusions, or other imperfections, but color is of most importance. Though lacking the toughness of jadeite, chrysoprase is often harder, more translucent, and produces better polish and luster.

The most important type of nephrite jade is a darker green, translucent to opaque, a color often called “spinach.” In appearance it has an oily luster, although the stone itself is not oily.

A 10X loupe will provide some visual clues to tell the three gems apart. The internal structures of both nephrite and jadeite jade are very different from chrysoprase, as can be seen if you shine a bright light through the stone from behind. With jadeite and nephrite, you can see fibrous, felt-like, asbestos-like intertwinings; of the two, nephrite will be more fibrous and jadeite more granular. Chrysoprase is microcrystalline, meaning that it will look homogenous by comparison.

For the more gemologically inclined, a specific gravity liquid set is the fastest, easiest, and most reliable way to distinguish the three gems (see chart for specific gravity values). However, the liquids used in this test are toxic and should be handled with care.

A chrysoprase, lapis lazuli, 18K gold, and silver pin from Michael Zobel.

If it’s possible to examine the stones through a table-top spectroscope, jadeite will show a 437-nm line and “chromium lines” in the red end of the spectrum, while chrysoprase will not. Hand-held spectroscopes produce unreliable results, especially the less expensive models.

Even if the stone is jade, there are still potentially deceptive practices to watch out for, such as dyeing, bleaching, use of stabilizing polymers, and creating jade doublets and triplets.

The most useful tool with the jades is the inexpensive Chelsea filter, easy to use and fastest of all gem identification tools. Natural jadeite, nephrite, and chrysoprase will all look green through the filter. With the filter held close to the eye and as much light as possible on the stone, if any of the three appear red or reddish, this is almost always proof that the stone has been dyed.

Dyeing is much more common with jadeite than with nephrite or chrysoprase, but it’s something to watch for with all three gems.

Chrysoprase can often be found in colors close to that of jadeite. Chrysoprase and fire opal earrings, photo courtesy AGTA.

The Chelsea filter cannot be used to identify what is called “B jade,” that is, jadeite that has been bleached (immersed in acid) to remove the brown impurities caused by iron and then filled with a polymer resin to stabilize it. The only sure way to tell if the gem is B jade is to use infrared spectroscopy, which is only available in professional laboratories.

Just as opal is made into doublets, so is a thin layer of gem-quality jadeite sometimes glued over a different base to create a better-looking stone. Jadeite trip-lets also appear on the market. Sometimes the triplet is made of three hollowed cabochons fitted one inside the other, stuck together with glue the color of mint jelly. The layers of a jadeite doublet or triplet can usually be detected with a 10X loupe.

As with all gems, buyers should beware of prices that are too good to be true. When doing research for this article, retailers told me more than once, “It’s best only to deal with suppliers you know and trust.” If at all in doubt, have a trained gemologist check it out. As the poet Longfellow wrote, and Plato before him, “Things are not always as they seem.”

Donald Crowhurst is a retired minister with a Graduate Gemologist degree from the Gemological Institute of America. Originally from Newcastle, Australia, he now makes a living as a freelance writer based in Calgary, Canada.