Given the expanding nature of the global market, other sites could soon be challenging London, New York and Hong Kong for auction-house business. Christie’s is particularly keen on expanding into less-trodden territory. “We don’t like to have all our eggs in one basket,” says François Curiel, the firm’s global jewelry chief.

One of the places Curiel has his eye on is the billionaire’s haven of Dubai, where Christie’s began holding sales in January 2007. Its auction there last November brought in $16.5 million. In time, Curiel thinks Dubai could be the new Geneva. Like the Swiss city, it is a port franc and surrounded by countries and cities flush with wealth and bullish buyers—in Dubai’s case, Mumbai, India; Saudi Arabia; the emirates Qatar and Abu Dhabi; and, an unlikely but emerging source of buyers, Iran. But for the moment, despite the $1.55 million winning bid Curiel took for a diamond fringe necklace by Van Cleef & Arpels last November, the Dubai market remains embryonic. The diverse content of the Christie’s sales there—from items like the Van Cleef necklace to lower-priced watches not generally included in its auctions elsewhere—suggests that the aim is to attract a range of buyers.

Bonhams, too, sees potential in the Persian Gulf sheikhdom. It held its first sale of jewelry and watches there on March 4, taking in a little over $2 million.

Whatever the venue, a new crowd of bidders is evident at the auctions. Russians, for example, accounted for 8 percent of Christie’s jewelry sales last year, a proportion that rises to 20 percent when underbidders are included.

Their passion for diamonds and contemporary jewelry notwithstanding, these oligarchs are no match for their subcontinental counterparts in the pursuit of glittering prizes. “Indians have had jewelry in their blood longer than anyone else,” believes Sotheby’s Bennett, who also notes that they differ from European collectors both in the gems they most desire and in their approach to winning them: “The amount of time they spend looking at a pearl necklace is extraordinary.” At Christie’s Geneva in November 2005, aggressive underbidding by the Mumbai trade helped push the price of the famous diamond-mounted oval Perle Napoléon to SF3.27 million ($2.5 million).

The auction champions, though, are still white diamonds, as evidenced by the SF18.2 million ($16.2 million) that the Guess fashion company honcho Georges Marciano paid for an 84.37-carat gem at Sotheby’s Geneva last November. The Chloe, as Marciano named it after his daughter, became the second most expensive diamond ever sold at auction, just behind the pear-shaped Star of the Season, which brought $16.5 million in May 1995, also at Sotheby’s.

Worldwide demand for diamonds has burgeoned, driven in part by recent fluctuations in the financial markets, which make major gems more desirable, as an alternative investment. This has led to a rise in value for both set and loose stones. De Beers, the South Africa– based giant that controls the lion’s share of the diamond market, from mining through marketing, has hiked prices considerably. That, in turn, has squeezed the gem-cutters of Antwerp, the center of the diamond trade, who buy rough stones in dollars and then pay for labor and materials in euros (see “Rock Stars”).

The auction houses, however, are certainly profiting, thanks to what Curiel calls a “host of clients who are new in the market and do not know the old prices.” And colored diamonds have reached previously unseen price levels, with important blue or pink diamonds now commanding $1 million per carat. Last October at Sotheby’s Hong Kong, a 6.04-carat, vivid-blue diamond ring realized HK$61.9 million ($8 million), or about HK$10.25 million ($1.32 million) per carat. Yellow diamonds, the most common color, currently cost less than other hues and could well rise in price, says Curiel. Those with intense coloration are already through the roof: The two dazzling Donnersmarck Diamonds—an 82.48-carat pear shape and a 102.54-carat cushion cut that once belonged to a 19th-century Parisian courtesan—brought a combined SF9.67 million ($7.9 million) at Sotheby’s Geneva last May.