A diamond-encrusted crystal Faberge egg that once belonged to the Russian royal family has sold in London for a record £22.9 million ($30.2 million).

The winter egg, considered one of the legendary jeweler’s most beautiful creations, was bought by an anonymous bidder on Tuesday, Christie’s auction house said.

Set with 4,500 diamonds, it was commissioned by Tsar Nicholas II in 1913 as a gift for his mother.

The previous auction record for a Fabergé egg was £8.9 million in 2007.

Agence France-Presse quoted Christie’s auction house’s Margo Oganesian as saying: “Today’s sale results set a new world auction record for a Faberge work and once again confirms the lasting significance of this masterpiece.”

The 8.2 cm high (3.2 in) egg was created by Carl Fabergé based on a design by Alma Theresia Pihl, one of only two female craftsmen at the St. Petersburg jewelry company.

It’s carved from crystal and embellished with rose-cut diamonds and a platinum snowflake pattern.

The egg opens to reveal a small basket of white quartz flowers.

Only 50 eggs were made by the Fabergé estate for the Romanov family of the Russian Empire, and the Royal Winter Egg is one of only seven remaining in private hands.

Others are either missing or owned by institutions or museums.

The eggs were made from 1885 until 1917, when Tsar Nicholas II was forced to abdicate.