Petra Diamonds was founded by Adonis Pouroulis in 1997 and was first listed on the Alternative Investment Market later that year.

On 14 September 2011, Petra purchased Finsch as a fully staffed, operating mine from De Beers for a total consideration of ZAR1.4 billion.

In line with the South African Mining Charter, the Petra Diamonds Cullinan Consortium included broad based Black Economic Empowerment partners.

The current operating levels include the B-Cut at a depth of 747 metres, and beneath that lies the Centenary-Cut ("the C-Cut"), a world class diamond resource.

In 1985 it lost the record to the Golden Jubilee, which was found in the same mine as the Cullinan and weighed 545.67 carats (109.134 g) in its polished state.

Immediately after completing the preparations, production from the open pit commenced and proceeded to a depth of 270 metres.

Underground production briefly took place in 1982 but ceased soon thereafter due to the 1981 slump in the diamond market.

[13] Petra agreed to acquire the Williamson Mine in Tanzania in September 2008 from De Beers and completed the acquisition in February 2009.

[14] The Williamson mine, which was discovered in 1940, has a reputation for the production of large, high value diamonds, with special stones (classified as larger than 10.8 carats (2.16 g)) produced regularly.

It has an average mining depth of 65 metres (90m at the deepest point) and a very low stripping ratio.