Blue diamond, mined in India 300 years ago, to be auctioned
A 6.16-carat blue diamond, which was mined from the Golconda mines in India over 300 years ago, is expected to fetch up to $5.2 million (â¹34 crore) at an auction in Switzerland next month. The Farnese Blue diamond was first presented to Queen of Spain Elisabeth Farnese and later passed down through royal families in Spain, Italy, Austria and France. 