The Farnese blue diamond, which was passed down through European royal families for some 300 years, sold at auction in Geneva on Tuesday for 6.7 million Swiss Francs , beating its estimate of 3.5-5.0 million Francs.

The 6.16 carat, dark grey-blue stone from the Golconda diamond mines of India was first given to Elisabeth Farnese, daughter of the duke of Parma, in 1715 when she married Philip V of Spain.

An oval diamond ring weighing 50.39 carats, which had been expected to fetch between 6.96 million and 7.68 million Francs, went for 8.1 million Francs.

A round brilliant-cut diamond weighing 51.71 carats sold for 9.26 million francs, just topping its estimate of 7.87 million-9.1 million.