Bid like the pros with the help of catalogs

If the idea of buying antique jewelry at auction appeals to you, here are some tips from Franois Curiel, executive vice-president, jewelry, at Christie's in Manhattan. This auction gallery holds about l5 jewelry sales per year in the United States, eight in London, and two in Geneva. ``Many people are intimidated by the thought of buying at auction,'' says Mr. Curiel, ``particularly when they do not know very much about the items being sold. Since the more you know about a piece of jewelry the more confident you will feel in bidding on it, the best way to find out is to consult the sources available to you -- the staff of experts and the catalogs.''

Catalogs, which carry photographs of many pieces, are a good source of information. ``They describe each piece and give its provenance and the estimated price that our experts expect it to sell for.''

A pre-sale estimate, says Mr. Curiel, is determined by the quality of the stones: the type of precious metal used; the size, age, and rarity of the stones; intricacy of workmanship; maker's mark; provenance (previous owners and history); and the prices similar pieces have brought recently at auctions around the world.

In some cases, certain pieces may be sent to the Gemological Institute of America to test quality or origin. When determining the value of colored stones, such as rubies and emeralds, color is by far the most important factor. In the evaluation of a diamond, however, clarity, or freedom from flaws, is just as important a consideration as color.

Each item up for sale goes on view about a week before the auction, with experts on hand to answer questions. Private viewings can also be arranged. By consulting these experts, and by careful questioning and listening, a viewer can learn a great deal.

If you decide to attend an auction and bid in person, you must first register, by phone or in person, before the sale date or just before the auction begins.

If you are unsure about how to bid, ask for assistance from the Customer Service department. The opening bid and subsequent increments are made at the auctioneer's discretion. Usually, however, bidding proceeds at increments of 10 percent or less over the last bid.

If you cannot attend an auction, you can always submit an ``order bid'' filled out on Christie forms. This form authorizes Christie's to bid for you. If you mail such a form, it should arrive at least 24 hours before the auction takes place.

You can also authorize someone else to bid for you, or make special arrangements to bid by phone.

Christie's charges a 10 percent buyer's premium, which is added to the final bid price. This means that if you successfully bid $1,000 on an item, your total cost will be $1,100, plus sales tax where applicable.

What are the advantages of buying at auction? ``Prices at auction are in many cases lower than retail,'' Mr. Curiel explains, ``as the willing buyer `sets his own price' by bidding voluntarily. In addition, the selection of `old' pieces of jewelry is often more extensive than that which is available in retail stores.''

For young collectors whose budgets are modest, Mr. Curiel suggests looking at the ``Retro'' style pieces made by fine jewelers in the early 1940s and '50s.

``For under $2,000,'' he says, ``such a customer could buy at auction today good-looking jewelry made by such leading jewelers of the period as Tiffany, Cartier, [and] Van Cleef & Arpels in New York, and Trabert & Hoefer of Paris.''

The next sale of fine jewels at Christie's takes place March 5 and will feature many styles, including both art deco and ``Retro,'' as well as estate jewelry dating from the late 18th and early 19th centuries.