Our Business Model

With a high growth profile, an industry-leading team and one of the world’s largest diamond resources of 312 million carats, Petra offers a unique and high quality investment opportunity, providing direct exposure to late cycle diamonds.


Project appraisal

Central to our approach is the identification of the right assets, where the Company can add value through capital and expertise. We focus on assets with the potential for significant production and good operating margins.

Geographic focus

Petra’s portfolio is located in Sub‑Saharan Africa which produces circa 60% of the world’s diamonds by value.

Sustainable operations

Petra focuses on longer-life assets with significant remaining diamond resources and structures its operations with the long-term viability of the project in mind.

Mining and development

Petra’s operations are focused on ‘hard rock’ kimberlite pipe orebodies, as opposed to alluvial deposits.

Open pit and underground

Petra operates one open pit mine in Tanzania, where ore is drilled and blasted from the surface. The Company also operates four underground mines in South Africa, which use ‘cave’ mining to access one block of ore at a time, exploiting gravity and the kimberlite’s inherent weakness to enable the ore to collapse autonomously.

Accessing undiluted ore

By opening up access to new blocks of ore at its underground mines, Petra will be able to mine pure kimberlite ore, undiluted by waste rock, thereby substantially increasing the grade (by circa 50%).


Ore is passed through the processing plant to extract the diamonds from the rock.


The rock is first crushed to a particular size. The crusher settings vary from mine to mine, depending on the size and value of diamonds produced by that orebody.


Ore goes through a series of screens, jigs and scrubbers before being subjected to a gravity separation process to remove lighter particles and create a concentrate of diamond-bearing material.

Final recovery

Diamonds are recovered primarily with X-Ray methods and grease back up.

Rough diamond sorting and sales

Rough diamonds are sorted into ‘lots’ (parcels of one or more diamonds depending on the size and quality) and then made available for viewing.

Competitive tenders

Buyers from all over the world attend Petra’s tenders in Johannesburg, for the Company’s South African production, or Antwerp, where Williamson production is sold. Confidential bids are placed in an electronic system on one or more lots of the buyer’s choice and the highest bid wins the parcel.

Product assurance

Petra will never sell rough diamonds mined from unknown sources, thereby guaranteeing their ethical origin.