From an article in Asiaweek:

Is it a good time to buy jadeite jewelry?

Absolutely. It's a buyer's market. Prices started going up around 1995, and peaked in 1998. Since then, prices have gone down - jadeite prices have essentially followed the decline of the Hang Seng index. Now is also a good time to buy before the mainland Chinese market opens up. As the Chinese become richer in the next three to five years, collectors and investors from the mainland will probably start buying up jadeite, which is a very traditional Asian purchase. This will certainly push up prices, because there's a limited supply of the finest quality jadeite.

Christie's held an auction earlier this month. How did jadeite do?
About 66% of the jadeite lots were sold. The smaller pieces did very well. For example, a bamboo-and-jadeite brooch sold for $5,769, which was double the presale estimate. The big pieces all sold just within their estimates, however, probably because there weren't a lot of buyers at the top end of the market. If there were no Sept. 11 attacks, the bidding would have been much better.

How much should you pay for a significant jadeite piece these days?

You could probably buy a very pretty piece for about $25,000. If it's rare and of high quality, it will appreciate in value [given today's low prices]. It could double or even triple. Design is very important. If the jadeite is part of a unique piece of modern jewelry, for example, that makes it more rare - and more desirable.

What about lower priced jadeite pieces in jewelry stores and jade markets?

You can buy jadeite [that are less brilliantly green] for about $400, but that won't give you as good an investment return. That kind of jadeite is mostly for your own personal enjoyment. Ultimately, buying jewelry is a very personal thing. Some collectors may not buy the highest grade of jadeite because they don't like it as much as they do other jewelry pieces [with less green jadeite] that they think are more beautiful.

How do you distinguish between top quality and lower quality jadeite?

No two jadeite pieces are the same. You need to look for color, transparency and
clarity. A slight difference in the type of green makes a huge difference. The most valuable jadeite are pieces that have a brilliant saturation of green without artificial treatment. The more transparent jadeite is, the more valuable. And it must have a good, smooth texture. Age isn't necessarily important - after all, you can find lots of ugly pieces from the Qing Dynasty.