The Hen Egg (1885)

The Hen Egg started all of it. Tsar Alexander III commissioned it as an Easter gift for his wife, Maria Feodorovna, and it's deceptively plain from the outside -- a matte white enamel shell that gives no hint of what's inside. Crack it open and there's a golden yolk; inside that, a golden hen; and inside the hen, originally, a diamond miniature crown and a ruby pendant, each nested surprise smaller and more precious than the last. Every Imperial egg that followed, for the next three decades, was chasing the idea this one invented first.