A rare 1904 tiara by Fabergé, jeweller to the Russian Tsars, is up for auction at Christie's and expected to fetch up to €300,000.
The tiara was made in 1904 as a wedding gift from Germany's Frederick Francis IV, the last Grand Duke of Mecklenburg-Schwerin, to his bride, Princess Alexandra of Hanover and Cumberland.
The Grand Duke's mother was a Russian duchess and keen collector of Fabergé jewels, who encouraged her 22-year-old son to order the gift from the jeweller's atelier in St Petersburg.
It arrived a month later than the wedding after the duke dallied over the choice of gemstones and Fabergé's sketches went missing, as detailed in letters between Russia and the German court.
"It's an absolutely beautiful tiara with nine graduated aquamarines," said Max Fawcett, a jewellery specialist at Christie's in Geneva, on Wednesday.
"There are very few Fabergé tiaras in the world market today and when they do come up for auction they always gather a lot of attention. We expect fireworks in the saleroom come May," he added.
The tiara design features forget-me-nots tied with ribbon bows, to signify true love, which are pierced by Cupid's arrows.
It will be sold in Geneva on May 15 alongside other gems, including an early 19th-century Colombian emerald and diamond fringe necklace owned by the Duke of Aumale and given to his goddaughter Princess Helene of France, the Duchess of Aosta.