MONACO—In three days of auctions, from July 29 through 31, the Paris firms Tajan SA and Artcurial offered 2,280 lots of jewelry, watches, design and modern and contemporary art. The total number of items put on the block was up 25 percent from 2007—a significant increase that led auction observers to wonder whether the market could absorb such a glut.

Both firms had cause for satisfaction. Tajan SA outdid Artcurial in total sales, €9.18 million ($14.4 million) to €5.43 million ($8.5 million), but the Artcurial figure represented a 26 percent increase from last year, while its rival’s was a mere 2.6 percent rise.

Artcurial’s hefty hike was owed to the performance of the star lot of its jewelry sale: a 14.96-carat emerald-cut diamond ring in a yellow-gold setting from Maison Gérard, consigned by a private individual from the Near East. Word in the trade was that this magnificent market-fresh diamond was worth around €1.2 million ($1.9 million), so the printed estimate of €800,000 to €1 million ($1.3–1.6 million) attracted fierce competition from the moment the auctioneer, François Tajan, started the bidding at €500,000 ($786,000). At the €1 million mark, there were still seven contestants for the prize, which ultimately went for €1,471,712 ($2.3 million) to a bidder on the phone with Artcurial’s international consultant Ardavan Ghavami. The underbidder was an Indian dealer at the back of the salesroom.

The Gérard ring was the only big seller at either firm’s jewelry sale. François Tajan concedes that the market was “a bit up and down,” with 1940s jewelry notably in the doldrums, but he stresses the enthusiasm for the gemencrusted accessories, citing a diamond, gold and ruby Alfred Dunhill lighter (est. €800–1,000; $1,300–1,600) that reached €10,000 ($16,000) and a coral, gold and mother-of-pearl powder compact by Lacloche (est. €3–4,000; $4,700–6,300) that shot up to €17,349 ($27,200).

Artcurial’s jewelry sessions brought in €4.44 million ($7 million), 30 percent more than last year’s sale even though more than half the 752 lots offered went unsold. The €4.54 million ($7.1 million) that Tajan SA’s offerings brought in, although higher than its rival’s total, was achieved by a greater number of lots: 895. Six of these broke €100,000, including a circular 11.30-carat diamond ring with a platinum setting (est. €60–80,000; $94,000–126,0000) that fetched €162,335 ($255,000), but none came close to Artcurial’s Gérard ring. Nevertheless, the house expert, Chantal Beauvois, was pleased with the prices paid for designer pieces like Suzanne Belperron’s 1960 Nero’s Eye brooch (est. €100–120,000; $157–189,000)—set with a large, discshaped Colombian emerald—that vaulted to €146,226 ($230,000).

The watch market continues to thrive worldwide, and the Monaco sales, which brought in €1.94 million ($3.1 million), were no exception. Artcurial bested Tajan SA’s €881,170 ($1.4 million) total with a 235-lot auction that made €1.06 million ($1.7 million). Its highlight was a circa 1940 Breguet Perpetual Calendar desk clock (est. €50–80,000; $79–126,000) that fetched €88,000 ($138,000). But it was Tajan SA that achieved the highest price for a watch in Monaco: €99,136 ($156,000) for a Jaeger Le Coultre Master Minute Repeater (est. €70–90,000; $110–142,000), whose mechanical movement is visible through the silver openwork dial.

Artcurial halted its Monaco auctions of modern art a year ago, but Tajan SA continues its own sales there in this category. The house’s 106-lot session on July 30 was a success, taking in €3.35 million ($5.3 million), a more than 50 percent increase over last year. Serge Poliakoff’s Composition abstraite: rouge et bleue, 1958–60 (est. €250–350,000; $393–550,000), led the pack, achieving €309,800 ($486,000). Just behind was Le Douanier Rousseau’s Tête de mandrill dans la jungle (est. €120–150,000; $188–236,000), a small circa 1907 oil depicting a monkey from Paris’s Jardin des Plantes, which brought €247,840 ($389,000).