This is the world's most expensive diamond worth $57.73 million.

The world's most expensive diamond sold at an auction in Hong Kong for $57.73 million.

The name of this diamond is Williamson Pink Star Diamond and is sold at Sotheby's Auction.

The price of a diamond is $49.9 million and after including auction fee the price became $57.73 million, 

According to Forbes, this is the most expensive diamond in the world so far, which has been sold in the auction.

Friends, as you would know that all the good quality diamonds in the world have increased in price in the last 10 years.

One of the world's purest diamonds is the Pink Diamond found in the Williamson Mine in Tanzania, which was 32.32 carat

It is set on a pink, white, and gold (18 carat) ring. According to Sotheby's, it is also the second-largest pink diamond of its sort to ever be sold at auction. 

The Williamson Mine was established in 1940 and is famous for making pink diamonds.

According to Sotheby's, the most expensive diamond ever sold is the 59.6 carat Stuff Pink Star, which sold for 71.2 million in 2017.