This extraordinary blue-gray diamond (on the picture above) was given to Infanta Margarita Teresa by her father King Philip IV of Spain, on her engagement to her uncle Leopold I of Austria-one of the most historic events in European history.
This girl was the portrayed in Las Meninas), the most famous painting by Spaniard Diego Velazquez. In a political move, she was engaged to Leopold I, who later became the Holy Roman Emperor, and that was when her father gave his 13-year-old daughter the diamond as part of the dowry. Sadly she died aged only 21, having given birth to four child, of which only one survived beyond childhood.

It is believed that the Wittelsbach diamond originated from the Indian diamond mines, was passed into the Austrian and then Bavarian crown jewels, and was finally sold into private hands in 1931. It makes part of the current private collection since 1964.

According to a Christie’s spokesman said “no examples” of coloured diamonds comparable to the Wittelsbach have been put up in an auction before.
“Blue diamonds are rare and to offer a blue diamond of this size, quality, shape and provenance is truly extraordinary.” Actually, the nearest comparable coloured diamond sold at Christie’s was one just a third of the size, a 13.39 carat intense blue diamond that fetched £5.5 million ($8.9 million) in May.

In addition, “the appearance of a large blue diamond, among the rarest of colours, with a history that can be traced back to the 17th century and 300 years of royal connections will surely be a thrilling occasion for all collectors of exceedingly rare jewels and works of art.”

The Wittelsbach diamond is the star lot in Christie’s auction Jewels: According to estimates, the 35.56-carat gem, almost once inch in width, with a 300-year-old royal history, could raise up to 10million pounds ($16 million) when it goes under the hammer on December 10.

It is on public display at the auction house in King Street, St James’s, London, on Friday 5 December and from Sunday 7 to Tuesday 9 December.