For two years, the auction world lived with cautious estimates and withdrawn lots. Then the mood turned. Between the autumn of 2025 and the spring of 2026, the two leading houses, Christie's and Sotheby's, reported jewelry results that were strong on almost every measure: totals, sell-through rates, records for rare colored diamonds, and prices for signed vintage pieces that went far beyond what the stones alone would justify. Here is what the numbers show, and what they suggest about where collectors are putting their money. Jewelry sits inside the "luxury" category at the auction houses, alongside watches, handbags and cars. In 2025, that category grew at both houses: luxury turnover rose 22% to $2.7 billion at Sotheby's and 17% to $795 million at Christie's. Sotheby's jewelry department...