CAN'T-MISS COLLECTION Motion Picture We’ve seen diamonds in movable settings before, but never quite like this. French jewelry atelier Marie Mas, founded by designer Marie ­Cabirou, innovated a technique in which gemstones set back-to-back rotate forward and back—like dominoes on a hinge—switching color as they flip. Her latest ­collection, Swinging Stones, builds on this idea, but incorporates diamonds for the first time. The series includes exquisite high jewelry pieces and less blingy “daily wear” pieces that feature trails of multicolored tourmalines reversing to icy white diamonds. “I’m looking for movement and poetry in the mechanism’s complexity,” says Cabirou, a former jewelry designer for Christian Dior Couture. “My jewelry comes alive when it’s worn.” Top: Dancing Diamond Open Ring S in 18k rose gold with 0.37 ct. t.w. diamonds reversing to multic