Modernist Greta Lee Matt Winkelmeyer/Getty Images The Past Lives actress added a sleek Tiffany & Co. Elsa Peretti Bangle to her clean-lined Ralph Lauren dress at the Elle Women in Hollywood event in December. De Beers Courtesy of Brand The Winter Diamond Butterfly Ring spotlights rough blue-green and polished white diamonds at its center; price upon request, at De Beers Jewellers, New York City Cindy Chao Courtesy of Brand From the Art Jewel White Label Collection, this Branch Bangle is fully embellished with inlaid diamonds set in 18-karat white gold; price upon request, cindychao.com Messika  Courtesy of Brand Contrasting white-gold panels (either mirror polished or paved with snow-set diamonds) form the Bright Momentum necklace, with a 7.74-carat diamond at its center; price upon request, at Messika Century City, Los Angeles Martin Katz Courtesy of Brand A pair of white diamonds totaling 1.07 carats are surrounded by 164 more diamonds on the Rhomboid Diamond Drop Earrings; price upon request, at Martin Katz The Penthouse, Beverly Hills Romantic Nicole Kidman Gilbert Flores/Variety/Penske Media/Getty Images The star paired her Giorgio …