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Our Mines

Our portfolio incorporates major underground pipe mines and a large high-volume open cast mine

  • Finsch

    Finsch is a world-class mine which benefits from top quality infrastructure, including a modern processing plant

  • Finsch

    Finsch is a world-class mine which benefits from top quality infrastructure, including a modern processing plant

  • Finsch

    Finsch is a world-class mine which benefits from top quality infrastructure, including a modern processing plant


Finsch is one of the world’s significant diamond mines and South Africa’s second largest diamond operation by production (after De Beers’ Venetia mine). The mine benefits from state-of-the-art mining infrastructure, including a modern processing plant which was upgraded shortly before Petra acquired it at a total cost of approximately US$100 million.

Finsch has produced large, special diamonds in its history and produces a number of +50 carat stones annually. In addition, the mine is known for highly commercial goods of +5 carats and is rich in gem quality smaller diamonds.

Mining is currently transitioning from the block cave on the 630mL to the SLC over four levels from 700mL to 780mL. Development of the 11 kimberlite extraction tunnels of 70 level Phase 1 was completed and the tunnels handed over to production for slot cutting and ring blasting during H1 FY 2017.

In FY 2021, the Block 5 SLC production ramp up delivered 2.3 Mt. Overall production totalled 1.2 Mcts with a ROM grade of 53.5 cpht (FY 2020: 59.0 cpht).

Petra’s initial mine plan has a life to 2030, but resources in Block 6 and the adjacent Precursor kimberlite orebody, which sits next to the main body of the Finsch kimberlite pipe, are expected to prolong the actual LOM. The mine has gross resources of 37.72 Mcts.


Key Facts

Location Northern Cape Province, South Africa
Size of kimberlite pipe at surface 18ha
Mine start date 1967
Acquisition by Petra Diamonds September 2011
Acquisition cost ZAR 1.425bn
Ownership Petra Diamonds Limited: 74%1
Kago Diamonds (Pty) Ltd: 14%
Itumeleng Petra Diamonds Employee Trust: 12%
Total Resources
(inclusive of Reserves)
39.11 Mcts
Current depth of Resources 1,000m
Mining Method Block cave and sub level cave
Depth of current mining 700m
Mine Plan To 2030
Potential Mine Life +25 years

 1. Refer to Petra’s ‘Effective Interest in Mines’ in the following document: Analyst Guidance Explanatory Notes.


The Finsch kimberlite was discovered in 1960 and the mine was officially opened in 1967. Ore extraction was initially from the open pit. Sinking of the main shaft to access the mine from underground started in 1978. Two vertical shaft complexes, tunnels and ground handling infrastructure were prepared for the continuing exploitation of the pipe with the use of highly mechanised mining methods. In 2008 the treatment plant was upgraded at a cost of approximately US$100 million. On 14 September 2011, Petra purchased Finsch as a fully-staffed, operating mine from De Beers.

Finsch is known for highly commercial goods of +5 carats and is rich in gem quality smaller diamonds. Large, special diamonds are also a feature of the orebody, with a number of +50 carat stones recovered at the mine annually, and the mine also produces very rare fancy yellow diamonds.

Reserves & Resources

Category Tonnes (millions) Grade (cpht) Contained Diamonds (Mcts)
Probable 26.8 55.2 14.81
Sub-total 26.8 55.2 14.81
Indicated 27.0 68.7 18.56
Inferred 40.6 47.2 19.16
Sub-total 67.6 55.8 37.72

1. Resource bottom cut-off: 1.0mm.
2. Reserve bottom cut-off: 1.0mm.
3. Block 4 Resource tonnes and grade are based on block cave depletion modelling and include external waste. A portion of this remnant Resource reports into the current caving operations as low grade dilution.
4. Increased pit scaling and waste ingress have been included in the Reserve models
5. Block 5 and Block 6 Resource stated as in situ.
6. Remaining Block 5 Reserves are based on CA3D software simulations.
7. US$/ct values of 90-100 for ROM, based on expected sales values (with reference to FY 2021 sales results and considering rough diamond prices recovering to levels before the COVID-19 pandemic) and production size frequency distributions.

FY 2021 Results

Unit FY 2021 FY 2020 Variance
Revenue US$m 123.5 101.1 +22%
Diamonds sold Carats 1,602,312 1,348,181 +19%
Average price per carat US$ 77 75 +3%
ROM Production
Tonnes treated Tonnes 2,311,195 2,719,389 -15%
Diamonds produced Carats 1,237,219 1,603,678 -23%
Grade1 Cpht 53.5 59.0 -9%
Tailings Production
Tonnes treated Tonnes 0 211,541 -100%
Diamonds produced Carats 0 39,890 -100%
Grade1 Cpht 0 18.9 -100%
Total Production
Tonnes treated Tonnes 2,311,195 2,930,930 -21%
Diamonds produced Carats 1,237,219 1,643,568 -25%
On-mine cash cost per tonne treated ZAR 536 477 12%
Expansion Capex US$m 1.7 6.1 -72%
Sustaining Capex US$m 2.3 2.3 0%
Total Capex US$m 4.0 8.4 -52%

1. The Company is not able to precisely measure the ROM / tailings grade split because ore from both sources is processed through the same plant; the Company therefore back-calculates the grade with reference to resource grades.

Overall production totalled 1,237,219 carats (FY 2020: 1,643,568 carats), with ROM carat production of 1,237,219 carats (FY 2020: 1,603,678 carats) and an average ROM grade of 53.5 cpht (FY 2020: 59.0 cpht).

The contribution from underground ROM production decreased to 1,237,219 carats (FY 2020: 1,603,678 carats). In H1 FY 2021 ROM volumes mined were impacted by the expiry of the temporary Contops arrangement during September 2020, subsequently reinstated during October 2020 that remained in place until June 2021. In addition, the Finsch mine experienced higher than expected levels of waste ingress in a number of the upper levels of the Block 5 Sub Level Cave, which negatively impact the recovered grade. The Company conducted a detailed exercise to better understand this issue and has put a plan in place to mitigate the impact. This has included a revision to the draw strategy to limit planned draw tonnage, a build-up of inventory rings to allow for increased blasting from March 2021, and a change to the drill and blast designs to optimise ore extraction. This revised plan, along with the 1.2 Mcts mined during FY 2021, contributed to a decline in Finsch Reserves, which reduced from 18.48 Mcts as at 30 June 2020 to 14.81 Mcts as at 30 June 2021.

In the longer term, the Company will also investigate ore mixing programmes to better assist with the prediction of waste ingress. Furthermore, production at the Finsch mine in Q3 FY 2021 was impacted by very high rainfall.

Revenue increased by 22% to US$123.5 million (FY 2020: US$101.1 million) due to a combination of higher sales, related to the release of inventory held over from the prior year, and a slightly higher average value per carat of US$77 (FY 2020: US$75).

In July 2021 a re-engineering project was initiated at Finsch to comprehensively review and improve the mine’s cost bases and enhance operating margins at current throughput levels.

Mine Plan

FY 2021 Capex of US$4.0 million was mainly spent on infrastructure relating to the Block 5 SLC ground handling system including the third crusher, passes and tips.

FY 2022 Capex is guided at ca. US$21-25 million, primarily relating to the exploration drilling and feasibility studies associated with the new 3-Level SLC, underground development in 78 Level SLC Phase 2 and Stay in Business Capex.

Petra’s initial mine plan has a life to 2030, but resources in Block 6 are expected to prolong the actual LOM. The mine has gross resources of 37.72 Mcts.


Click on schematic to enlarge.

The orange blocks indicate the Block 5 SLC and the Block 5 Block Cave that are currently in our mine plan to 2030. The blue block indicates the potential future block to be accessed post 2030.

Mining Right

Finsch Diamond Mine (Pty) Ltd (“FDM”) holds a valid new order mining right (the ‘‘Finsch Mining Right’’) dated 15 October 2008. The Finsch Mining Right was initially issued to De Beers under item 7 of Schedule II of the Mineral and Petroleum Resources Development Act, 28 of 2002 (“MPRDA”) and was ceded to FDM by notarial deed of cession on 8 September 2011 and duly notarially executed and registered in the Mineral and Petroleum Titles Registration Office.

The Finsch Mining Right confers on FDM the exclusive right to mine for diamonds in relation to the areas it refers to until 14 October 2038. Pursuant to the MPRDA, the Finsch Mining Right is renewable (for periods of up to 30 years for each renewal) on the basis more fully set out in section 24 of the MPRDA.

Section 2 of the Mineral and Petroleum Resources Royalty Act No. 28 of 2008 (“the Royalty Act”) requires FDM to pay the South African Government a royalty for minerals recovered under the Finsch Mining Right. Pursuant to section 4 of the Royalty Act, the royalty is to be paid on gross sales in accordance with a defined formula set out in the Royalty Act. The formula applicable to rough diamonds is as follows: 0.5% + (earnings before interest and taxes, as defined in Section 5 of the Royalty Act / (gross sales x 9) x 100) but not exceeding 7%.

In addition, South Africa has a rough diamond export levy requirement of 5% as set out in section of the Diamond Export Levy Act 15 of 2007 (“Export Levy Act”). Producers are however exempt from this levy in respect of production that is exported provided that a certain percentage of their production is sold to local diamond beneficiation licence holders, on the basis more fully set out in sections 7, 8 and 9 of the Export Levy Act.

FDM is also subject to corporate tax in South Africa at the rate of 28% in terms of section 5 and other provisions of the Income Tax Act 58 of 1962.

There are no fiscal stabilisation provisions in place in relation to Finsch Diamond Mine.


  • Sept 2011 Acquisition by Petra
  • 1.2m carats FY 2021 Production
  • 37.72m carats Total diamond resource


finsch Diamonds

Two Finsch diamonds of 36 carat and 43 carat – November 2013