76 carat Archduke Joeseph Diamond to Auction

The world’s largest internally flawless and colorless diamond is set to auction at Christie’s in Geneva on November 13th. The cushion-cut marvel weighs in at 76.02 carats and is expected to sell for over $15 million.
It is said the origins of the stone can be traced to the Golconda mines in Central India. “The legendary Golconda mines in India produced some of the world’s most famous diamonds, including the Dresden green, the blue Hope, and the Koh-i-Noor (in the Royal Collection at the Tower of London),” said Rahul Kadakia, head of jewelry for Christie’s Americas and Switzerland.

The Archduke Joseph Diamond was named after one of its former owners, Archduke Joseph August of Austria, a military prince from the House of Hasburg. While there’s an air of mystery that surrounds the date the gem was initially acquired, all that is known is the royal family owned the stone until the 1930’s. Some time before then, the diamond was passed on to the archduke’s son, Joseph Francis who kept it deposited in a bank throughout World War II. The whereabouts of the diamond remained unknown until 1961, where it reappeared at auction in London.

Over three decades later, the diamond made another grand appearance at Christie’s in 1993 where it sold for $6.5 million (est. $10.5 million in current USD) to an anonymous buyer. In 1999, the diamond was sold in a private sale where it was subsequently re-cut by the new owner. It was during this process where the stone’s clarity grade was upgraded from Slightly Included (SI-1) to Internally Flawless (IF) after sacrificing 2.52 carats of the stone’s original weight.