What makes the best opal gem? There are many types of opal colorations, and each category has room for its own set of differences. Opal ranges from clear through white, gray, red, orange, yellow, green, shore, blue, magenta, rose, pink, slate, olive, brown and black.

I recommend:  Okanagan Opal Inc. has a handy list of what can make an opal gem more or less valuable. The International Colored Gemstone Association (ICA) can teach you more about "opal lingo" and why opal should be worn as much as possible, and the Gemological Institute of America (GIA) has lists of featured articles on the subject.

Expand your knowledge about opal jewelry selection by attending trade shows and conferences Association trade shows can provide valuable input from experts and expose you to a great range suppliers, dealers and manufacturers, and can create good networking opportunities.

I recommend:  The Tucson Gem and Mineral Show (currently the largest gem, mineral, bead and jewelry show in the world) is a worthwhile trip for any gem dealer or jeweler. I found out more about jewelry and opal jewelry there than anywhere else. Of the exhibits there, J.O.G.S. Gem and Jewelry Show is the largest expo.

Buy from trusted opal jewelry dealers or attend well-regarded auctions Go to auctions to get the best opal jewelry for the best price. Go to a dealer to ensure you are getting what you pay for. Look for local jewelers and opal dealers in your area. Whatever you do, showing up in person to an auction is always safer than ordering opal jewelry without having seen it first. When buying online, only buy from trusted dealers.

I recommend:  If you are going to buy online, Biz.com allows you to bid on opal jewelry in an auction. It may be more risky than the rest of my suggestions, but the prices are so forgiving, you might end up with something of quality for a very low price. Better known dealers like Zales and Jared: The Galleria of Jewelry won't offer you very rare or eccentric opal pieces, but they will get you reliable quality, popular styles and pretty good prices.

What makes the best opal necklace? Now that you know what kinds of opal gems you are looking for, you should know what kinds of opal jewelry you would like to sell, and how settings can change costs. Are you simply including opal in your store because you offer birthstone jewelry, and therefore do not need an extensive choice of creatively set opal stones? Are you planning on combining or buying combinations of opal gems and other stones, such as white diamonds? Is your service offering all types of metal casings, or only the most highly valued (white gold, platinum) or the lowest valued (aluminum, etc.)? Look at the differences in prices and the mastership of the jeweler when buying opal earrings: studs with a very small amount of metal showing should cost less than dangling, framed pendants. An opal bracelet should end up costing more than each. Don't forget, too, that the color of the opal gem should go with the color of the metal.

I recommend:  Blue Nile and Jewels For ME have good prices on white pinfire opal and white gold jewelry with diamonds. Opals Australia has a wide range of beautiful light opal doublets in everything from silver to yellow gold, with other precious stones, and in classic or highly stylized settings. It is also a good price and style guide.