An Australian mining company says it has unearthed a massive 404-carat diamond measuring more than 7 centimeters (2.7 inches) in length in the southern African nation of Angola.

The Perth-based Lucapa Diamond Co. said in a statement this week that the gem is the largest diamond ever discovered in Angola.

Lucapa chairman Miles Kennedy told the Australian Broadcasting Corp. that the white diamond is worth an estimated 20 million Australian dollars ($14.2 million).

The largest diamond ever unearthed was the 3,106-carat Cullinan diamond, which was discovered in South Africa in 1905. The gem was cut into smaller pieces that are part of the crown jewels.