In a rare achievement, the Petra Diamonds Ltd recently recovered a 23.16-carat pink diamond of exceptional colour and clarity from the Williamson mine in Tanzania.The stone is an example of the high-quality pink diamonds for which Williamson is known and is the most significant recovery by Petra from the mine to date, the diamond producer said in a press release.  Pink diamonds are only found in a handful of mines throughout the world and their rarity ensures that they are one of the most highly coveted of all the fancy colours. 

Geographically, the Williamson mine is located in the Shinyanga Province in Tanzania, and is the country’s only important diamond producer. The mine is an open pit operation based upon the 146 hectare Mwadui kimberlite pipe, which is the world’s largest economic kimberlite by surface area.  

The importance of this can be gauged from the fact that despite having been in continuous operation since 1940, the pit is only 95 metres at its deepest point due to the significant size of the deposit. Williamson produces high-quality diamonds, as evidenced by the average value of US$298 per carat in FY 2015.