Jewelry, one of the few categories that attract buyers across the entire spectrum of collecting specialties, brings in a significant chunk of change for the auction houses. In 2010, just through October, combined gem-sale totals at Sotheby’s and Christie’s had topped $500 million, with the November and December numbers yet to be added to the tally. While the market for sparklers has always been strong, the past three to four years have seen prices skyrocket. “Around $50,000 or $60,000 per carat for a white diamond used to be normal. With the sale of the Annenberg diamond we saw $240,000 per carat, a price that shocked even the most seasoned diamond dealer,” says Rahul Kadakia, Christie’s Americas head of jewelry, referring to the 32.01-carat D-color flawless stone that sold in New York in 2009 for $7.7 million. “Colored diamonds have also gotten stronger. There was a time when $400,000 or $500,000 per carat was the norm, but now it’s normal to pass the million-dollar mark. This was not the case three years ago.”According to Gary Schuler, director of the Sotheby’s jewels department, “Russia, China, and India have contributed to the dramatic increase. There is more demand and a finite amount of material.”

To better understand how the market has evolved, we computed the combined jewelry totals earned by Christie’s and Sotheby’s at four major market centers—New York, Geneva, Hong Kong and London—over the past decade, and examined how the wealth has been divvied up geographically.

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In an October 2010 sale at Christie’s New York that earned $52.66 million, the circa 1972 Bulgari Blue ring, set with a vivid blue and a white diamond, both triangular cut and weighing 10.95 and 9.87 carats, respectively, brought $15,762,500, setting a per-carat record of $1.4 million for a blue diamond. In an April 2010 sale at Sotheby’s Hong Kong that took in $52.69 million, a jadeite and diamond necklace and a pair of diamond pendant earrings fetched $5.57 million and $2.47 million, respectively.