This gold egg is covered in sky translucent-mauve enamel. A trellis of brilliant encrusted ribbons decorate the surface. At each intersection sits a four-looped bow. On top of the egg is placed a large portrait diamond, covering the year "1906". Another large portrait diamond sits at the base of the egg, under which a monogram once probably appeared.
Just like when you open a real egg, and it's shell cracks with jagged edges, so the "Swan Egg" opens up to reveal the surprise...
...A miniature swan dressed in platinum, with enameled eyes and beak. The swan rests in a basket dressed with garlands of flowers in three colors of gold, and a large aquamarine. Built into the swan is a mechanism that, when triggered, makes the swan spread its wings and move its feet and tail feathers. Then the head and neck proudly rise up, before settling down again.
The miniature swan was modeled after James Cox's "Silver Swan" automaton, from around 1773. In Russia the swan is considered a symbol of family life and the permanence of the bond of marriage. Tsar Nicholas II gave this egg to his mother, the Dowager Empress, to celebrate the year of her 40th wedding anniversary.
The "Swan Egg" now belongs to Edouard and Maurice Sandoz Foundation, Switzerland.
Here is a short video of James Cox's "Silver Swan" in motion!