Emerald

This elegant art deco shape received its confusing name during the 1920s, when it was typically used for emeralds. Characterized by a flat top and step-shaped side facets, an emerald-cut diamond pairs well with a clean setting. Donald Trump gave Melania Knauss this style.

2.53-carat emerald-cut diamond and .69-total-carat-weight diamonds in platinum, De Beers, $65,000;

debeers.com.

2.01-carat emerald-cut diamond with .34-total-carat-weight tapered baguettes in platiunum, Kwiat, $29,375; kwiat.com for stores.

1.5-carat diamond in platinum, price available upon request, Cartier; cartier.com for locations.

Emerald-cut diamond and baguette diamonds in white gold, Mauboussin, price upon request; mauboussin.com.

1-carat emerald-cut diamond in platinum, Tacori, price upon request; tacori.com.

2.14-carat diamond and 1.33-total-carat-weight diamond side stones in platinum, Christopher Designs, $45,000; christopherdesigns.com.

1.5-carat emerald-cut diamond and 2.72-total-carat-weight baguettes in platinum, Vera Wang, $23,550; Bergdorf Goodman, 888-774-2424.

.82-carat green iolite and pave diamonds in 18kt yellow gold, Leslie Greene, $4,905; at Saks Fifth Avenue.

.56-carat emerald-cut diamond and .40-total-carat-weight round diamonds in 18kt white gold, Christopher Designs, $5,700; 800-955-0970 for store locations.