The Farnese Blue diamond a 6.16 carat pear shaped, GIA graded as Fancy dark gray blue.
Sotheby’s Magnificent Jewels and Noble Jewels in Geneva will auction the diamond on May 15.
The history of the diamond : Recovered in Indian Golconda region, the diamond was first given to Elisabeth Farnese, Queen of Spain in 1714.
It then passed to her son Philip, Duke of Parma, and through various Italian nobles ending with the Habsburg family.