In the 1930s, few jewelry makers were as relentlessly creative as Cartier. The Parisian house peppered its pieces with unusual gemstones and nontraditional materials throughout the decade. But it was a rare piece—for Cartier or its contemporaries—that used rock crystal as a foundational element. And the two collectors who squared off on Dec. 10 to win this circa-1935 Cartier rock crystal bangle at Christie’s Magnificent Jewels sale knew as much. “In general, Art Deco jewelry by Cartier is among the most sought after by jewelry collectors of this period,” says Tom Burstein, senior vice president of the jewelry department at Christie’s. “Cartier bangles and bracelets made of rock crystal…rarely come up for auction.” The pristine condition of the nearly century-old crystal added to the appeal of the bracelet, whose original estimate was a mere $25,000–$35,000. “A jewel like this really transcends the rarity of many pieces seen at auction.”