Tiffany & Co.
This romantic cut dates back to Louis XIV, who kept heart-shaped diamonds in his vast collection and Kirsten Dunst received one onscreen as Marie Antoinette. More recently, the style really began to shine in the early 20th century, when diamond-cutting techniques improved. 1-carat heart-shaped Bezet-set diamond in platinum, Tiffany & Co., $11,100; tiffany.com. Read MoreLess