For the past five decades, gemologist Alexandre Reza has been one of Paris's--and indeed, the world's--most exclusive jewelers, a master artisan and exporter based in Place Vend me, the heart of fashion and luxury. To experience his ornaments is to discover history reborn: The diamonds, sapphires, emeralds, and rubies of his collections have seen the most extravagant centuries and epochs, from French monarchies to Persian dynasties to the Italian...