A crystal and diamond-studded Fabergé egg once owned by Russia’s imperial family has sold in London for a record 22.9 million pounds. The celebrated Winter Egg, regarded as one of the finest creations of the legendary jeweler, was purchased on Tuesday by an anonymous bidder, according to Christie’s.

Commissioned by Tsar Nicholas II in 1913 as an Easter gift for his mother, the piece is adorned with some 4,500 diamonds. Its sale shatters the previous auction record for a Fabergé egg—8.9 million pounds, set in 2007.

“This result sets a new global auction benchmark for a Fabergé work, underscoring the enduring significance of this masterpiece,” said Christie’s specialist Margo Oganesian, as reported by AFP.

Standing 8.2 centimeters (3.2 inches) tall, the egg was crafted under the direction of Carl Fabergé and designed by Alma Theresia Pihl, one of only two women designers at the jeweler’s St. Petersburg workshop. It is carved from rock crystal, embellished with rosette-cut diamonds, and accented with platinum snowflake motifs. Inside, it opens to reveal a miniature basket of white quartz flowers.

Only 50 imperial eggs were created for the Romanov family between 1885 and 1917, and the Imperial Winter Egg is one of just seven still in private hands. The rest have either been lost or now reside in museums and institutional collections.