Petra Diamonds Limited is a United Kingdom-based independent diamond mining company and a supplier of gem quality rough diamonds to the international market. The Company's segments include Mining, Corporate and Beneficiation. Its Mining segment is engaged in the extraction and sale of rough diamonds from mining operations in South Africa and Tanzania. The Company's portfolio incorporates interests in two underground mines in South Africa (Cullinan Mine and Finsch) and one open pit mine in Tanzania (Williamson). Cullinan Mine is its flagship asset and a kimberlite, which has rare and Type IIb blue diamonds and high-quality Type IIa white diamonds. The Finsch mines produce special diamonds and a number of +50 carat stones annually. Finsch mine also produces very rare fancy yellow diamonds. Williamson mine produces rounded white and bubble-gum pink diamonds.