InStyle Weddings

This diamond shape has a rich legacy. The dramatic Asscher-cut, named for the British royal family's gem cutters, originated in 1902 and has stepped sides and a high crown to shed a gentle light. The cushion, which Ashlee Simpson-Wentz wears, dates back to the early 19th century and has curved sides and rounded corners to shine softly, while the flirty princess-cut, dreamt-up in London during the swinging '60s, has 49 to 144 facets for a hall-of-mirrors effect.

7.11-carat Asscher-cut diamond in platinum, De Beers, $805,000; debeers.com to arrange a viewing.

Note: Also available with 1.08-carat center stone for $16,000.