![1870NE02A.jpg](https://gazette-eu-west2.azureedge.net/media/4412/1870ne02a.jpg?width=750&height=500&mode=max&updated=08%2f03%2f2017+16%3a47%3a00)
The rare 35.56 carat cushion shaped blue diamond - the size of a postage stamp - was purchased by King Philip IV of Spain in 1664 and was included in the dowry of his daughter, the Infanta Margarita Teresa, when she married Leopald I of Austria.
It was then passed down through the Bavarian Royal family until offered at auction in 1931, where it failed to sell and then vanished only reappearing in 1962, when a jeweller refused a request to re-cut it.