For any diamond with a provenance that pre-dates 1725 there is one absolute: where it’s from. Diamonds mined before this gemological line-in-the-sand were from India and nowhere else. It wasn’t until 1725 that another source was discovered in Brazil. But for more than 1,000 years, Indian diamonds were all the world knew, adorning the globe’s elite, hungry for the stone’s magic and fire.

The most prized diamonds came from a specific region – the kingdom of Golconda, a geographical territory that no longer exists but comprised of the present-day states of Telangana and Andhra Pradesh. Here the diamonds were large, of varying hues, and notably transparent – specifically Type IIA – so devoid of nitrogen, a quality that made them the rarest of all. The Kollur mine on the banks of the River Krishna would yield the most, or certainly the most extraordinary. Diamonds from here would include the Koh-i-Noor, the Regent, and the Hope, iconic stones that would in turn endow their place of birth with an almost mythical status.

But as with all good things, it would come to an end. By the close of the 19th century the mines would stand silent, centuries of digging having depleted the ground of all its great treasures. The world’s focus duly shifted to South Africa and its newly discovered deposit-rich soil.

To own a Golconda diamond therefore is to connect with a different time - to a land ruled by sultans and maharajas, where spices were currency and legendary stones were born. And now another can be added to the roll-call, the Farnese Blue, 6.16 carats of pear-shaped Fancy Dark Grey-Blue, gifted in 1715 to an Italian princess, Elizabeth Farnese to mark her marriage to the King of Spain. Its journey to Madrid is a story of luck and miraculous escape; of the twelve ships carrying an assortment of wedding treasures it was the only vessel to survive a hurricane. And there it remained in Europe, descending through successive generations of noble families, known only to them and their family jewellers.


GOLCONDA FORT, RUINED CAPITAL CITY OF THE ANCIENT KINGDOM OF GOLCONDA 1518–1687 © PETER HORREE / ALAMY STOCK PHOTO

As we are constantly reminded, exceptional diamonds are rare, with the world’s supply in decline. But the number of Golconda diamonds, by the very nature of their origins, is already finite. There are no more stones that can be added to the yield that was dug from the ground more than 300 years ago. To re-discover an unknown gem is rarer still; add in a royal ownership, and an unusual colour, and the cocktail is an intoxicating one. The Farnese Blue may have been mined several generations ago, but its emergence once more marks a thrilling re-birth for this storied, bewitching stone.