This egg was made to commemorate 1896 coronation of Tsar Nicholas III and his wife, and given by him to his wife Empress Alexandra Feodorovna.
The egg is made of gold, covered with translucent lime yellow enamel on a guilloché field of starbursts, inspired from the cloth-of-gold robe worn by the Empress at the coronation. Over the whole egg there is then a trellis work of greenish gold laurel leaves, with an Imperial double-headded eagle, enameled opaque black and with a rose cut diamond on it's chest, at each intersection. On top sits a large portrait diamond within a cluster of ten brilliant diamonds. Through this stone the monogram of the Empress can be seen. At the bottom of the egg there is also a diamond-surrounded portrait diamond, through which can be seen the date of it's making.
Inside a velvet-lined compartment sits the surprise - a precise replica, four inches long, of the eighteenth-century Imperial coach that carried Alexandra to her coronation. Enameled in the coache's original colors, the little replica is then surmounted by the Imperial Crown in rose cut diamonds and six double-headed eagles on the roof. The windows are made of rock crystal, and the platinum tyres decorated with a diamond-set trellis in gold. On either door there sits an Imperial eagle in diamonds. The miniature is complete with moving wheels, opening doors, actual C-spring shock absorbers and a tiny folding step-stair. Missing from the replica is an emerald or diamond pendant that hung inside the coach, and a glass-enclosed jadeite stand for the display of the carriage, as well as a stand made of silver-gilt wire.
When the Hermitage undertook to refurbish the original coach some years ago, they actually used the tiny replica to work from. That's how well it was copied!
The "Coronation egg" has been shown in temporary exhibits at different museums around the world. Currently it is owned by one of the Russian oligarchs - Viktor Vekselberg.