The fifth egg - from 1889 - is also missing. It's called the "Nécessaire Egg", was designed as an etui, and probably contained the surprise of a set of thirteen diamond-encrusted woman's manicure set. this is not certain though, since no pictures of the egg or it's contents exist...
Then, finally, I can show you a picture of an egg that hasn't been lost: The "Danish Palaces Egg" from 1890!
The outside of the egg is divided into twelve sections of enameled gold, divided by lines of rose-cut diamonds. Wherever the lines meet there's an emerald, and the whole thing is crowned by a medallion of radiating leaves and a cabochon star sapphire! When the egg is opened the surprise unfolds as a row of little watercolor pictures - signed by Konstantin Krijitski - painted on tiny panels made of mother of pearl.
The Tsar's wife - Maria Feodorovna - was born in Denmark, so all the little paintings depict yachts and mansions owned by her family in her land of birth:
The Imperial yacht "Polar Star"
The emperor's villa in Fredensborg park
The Cottage Palace
The Cottage Palace from another view
The imperial yacht "Tsarevna"