Kate Hudson may be the reigning queen of boho chic, but when she announced her engagement to Muse rocker Matthew Bellamy on the Today show, she showed off a ring that was more Park Avenue than Penny Lane. The more "traditional" nine-carat stunner features a platinum-set, emerald-cut diamond with tapered baguettes—could this mean the actress will start to embrace a more classic, sophisticated style in general? We can't really see her in a cashmere twin-set (or a Duchess of Cambridge-esque wedding gown for that matter—especially with a growing baby bump!), but anything's possible (Reese Witherspoon wore a frilly pink ballgown!). To capture Kate's elegant look, try one of these lovely options featuring emerald-cut diamonds.—Leigh Bond
From left: Platinum with emerald-cut diamond and tapered baguettes, $5,528, Iced Orchid; platinum with three-stone, emerald-cut diamond, $516,700, Jacob & Co.; platinum with emerald-cut diamonds and micropavé halo- and channel-set shank, $3,309, Art Carved; platinum Bella's Love engagement ring with emerald-cut diamond, $12,650, Katharine James Fine Jewelry.