Tiffany & Co.

America's great jewelry house began in 1837 as Tiffany & Young, a New York shop founded by Charles Lewis Tiffany and J.B. Young. Its most lasting contribution is the engagement ring as most people picture it: the Tiffany Setting of 1886, a six-prong solitaire that lifts the diamond above the band. The house also has a gift for hiring designers with their own voice. Jean Schlumberger joined in 1956 and brought his playful, nature-inspired high jewelry, while Elsa Peretti made sterling silver feel like a luxury material. Come here for the classic diamond solitaire, but look into the Schlumberger pieces if you want to see Tiffany at its most inventive.