This impactful Art Deco collar necklace from 1929 is an early Art Moderne jewel by Mauboussin, a French maison daringly led by Georges and his engineer son, Pierre-Yves. The turquoise cabochon buttons of definite sky-blue are set against the cloudy tones of the ridged milky chalcedony cylinders, spaced by contrasting arcs of diamonds and glossy black enamel rondelles. Clearly expressing Mauboussin’s disciplined, Machine Age aesthetic, this colorful, high-contrast necklace is a work of wearable modernism.