Williamson diamond mine
（重定向自Mwadui）
The Williamson Diamond Mine (also known as the Mwadui mine) is a diamond mine south of Mwanza in Tanzania; it became well known as the first significant diamond mine outside of South Africa. The mine was established in 1940 by Dr. John Williamson, a Canadian geologist, and has been continuous operation since then, making it one of the oldest continuously operating diamond mines in the world. Over its lifetime it has produced over 19 million carats (3,800 kg) of diamonds. The Williamson mine, once owned by its namesake Dr. Williamson and later nationalized by the government of Tanzania. Since February 2009 the mine is mostly owned by Petra Diamonds, with 75% ownership, the government of Tanzania owning the remaining 25%.