A 1,109-carat diamond the size of a tennis ball will auctioned next month in London. It is expected to net $70 million at the auction.

"Lesedi la Rona", which means "Our Light" in Setswana, is the second biggest diamond ever.

The diamond was found in Bostwana in November. It is believed to be 2.5 to 3 billion years old.  

The diamond is owned by Lucara, a Canadian-based company, and will be auctioned by Sotheby's.

Sotheby's says it is the largest rough, gem-quality diamond in existence today.

The diamond will be on display in New York on May 7th. The auction will be in late June.

The largest diamond in history is the 3,106-carat "Cullinan Diamond" that was found in South Africa in 1905. 

The "First Star of Africa," which now adorns the Royal Scepter, was cut from that diamond.