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Senior Management

Petra's senior management sit on Exco, holding monthly meetings with the CEO and CFO to assist them in their duties and in dealing with the day to day activities of the Company’s business.

Senior Management


Richard Duffy Chief Executive Officer

Mr. Duffy assumed the role of CEO in April 2019. He leads the management of the Company, implements the agreed strategy and runs the business on a day-to-day basis. He has 27 years of global mining industry experience, initially with Anglo American plc and then AngloGold Ashanti Limited, from its inception in 1998. In 2008 he was appointed Executive Vice President, Africa Region and continued in this role until January 2010 when he took charge of the Continental Africa Region, with operations in Namibia, Tanzania, Guinea, Ghana and Mali and a Joint Venture in the Democratic Republic of the Congo. In 2013 he was appointed Chief Financial Officer with direct responsibility for all financial matters including the formulation and execution of financial business strategy, debt and equity financing. In 2015 Richard became a co-founder and director of Africa Energy Management Platform, a private energy company targeting industrial and mining clients in sub-Saharan Africa.

Mr Duffy holds a B. Com degree from the University of Witwatersrand and an MBA from Henley Management College in the UK.


Jacques Breytenbach Chief Financial Officer

Mr. Breytenbach assumed the role of Finance Director in February 2018. He leads the financial management of the Company and is responsible for financing, treasury, financial controls, reporting, legal, investor relations, compliance and corporate governance.

Prior to this appointment, Mr. Breytenbach previously held the role of Finance Manager – Operations at the Company since 2006, with responsibility for financial management across the Group’s operations, before becoming Chief Financial Officer of the Group in June 2016. He joined Petra from Anglo Platinum, where he held various roles, culminating in his position as Finance Manager – Capital Projects, with oversight for Anglo Platinum’s extensive capital expansion programmes. He is a Chartered Accountant and a member of the South African Institute of Chartered Accountants.

Juan Kemp Chief Technical Officer

Juan joined Petra after the purchase of Cullinan Diamond Mine in 2008, becoming the Surface Manager and Group Metallurgical Manager for all 7 of Petra’s treatment plants. He was subsequently promoted to General Manager of CDM in 2011 and in July 2019 he was appointed to Project Executive, before later that year becoming Chief Technical Officer.

He has nearly 30 years of experience, with a depth of knowledge of both Koffiefontein Mine, having worked in a broad spectrum of operational roles before becoming Plant Manager under De Beers’ tenure, as well as Cullinan Diamond Mine where he acted as Metallurgical Manager for several years, having been an integral member of the team that re-engineered the De Beers South Africa business model. Before being promoted into the De Beers diamond mines, Juan worked at the East Rand Gold and Uranium Division of Anglo American in Johannesburg, where he worked as a Mineral Processing Engineer.

Juan graduated in 1994 as a Metallurgical Engineer from the Potchefstroom University for Christian High Education, South Africa and also holds an MA in Business Administration from the North West University Business School, South Africa.

Jaison Rajan Chief Operating Officer

Jaison joined Petra Diamonds as the General Manger of Cullinan Diamond Mine in July 2019. He has over 20 years of industry experience in various mineral commodities including heavy minerals, diamonds, manganese and coal. Jaison was appointed Chief Operating Officer at Petra Diamonds in 2022.

Prior to joining Petra he worked as General Manager at Khutala Colliery having worked for 8 years in a variety of managerial roles at BHP Billiton (South32) at the Wessels Manganese mine and Hotazel Manganese mines before this. Jaison also has an in depth understanding of Finsch Mine, having started his career there when it was owned by De Beers. During this time he acted a section leader, ensuring safe control, management, direction of underground excavations and infrastructure within the Ore Extraction Production area.

Jaison is an accredited Professional Engineer with a Mine Manager’s certificate of competency (South Africa), and holds a BSc in Mining Engineering, a post-graduate Masters in both Mineral Economics and Business Administration.

Gregory Stephenson Sales & Marketing Executive

Gregory has led the Sales team at Petra Diamonds since 2008. He oversees the preparation, valuation and marketing of Petra’s rough diamonds as well as managing the full sales process of the South African and Tanzanian production. Gregory has 35 years of experience in the buying and selling of diamonds.

Prior to joining Petra, Gregory spent ten years managing his own company, GDR Diamonds, Johannesburg, purchasing rough diamonds throughout southern Africa and providing independent valuations in Angola. Gregory’s broad knowledge of the diamond industry stemmed from his global experience at De Beers, London, where he started his career as a trainee diamond buyer in 1988. This included two years of intensive training in all facets and sizes of rough diamonds, the Overseas Purchasing Division where, over the span of 8 years, he went on multiple tours and secondments, which included Kinshasa, Brazzaville, Mbuji-Mayi, Kahemba, Luanda, Johannesburg and Antwerp.

Rupert Rowland-Clark Company Secretary

Rupert assumed the role of General Counsel & Company Secretary at Petra in June 2021. He leads Petra’s Legal, Company Secretary, Risk, Assurance & Compliance functions and reports into the Chief Executive Officer and Chairman.

He has over twenty years’ legal and executive experience, most recently at Tullow Oil plc, an African-focused FTSE 250 oil and gas company, where he was General Counsel from 2015 to 2020.  Prior to Tullow, Rupert was a mergers and acquisitions lawyer at global law firm, Freshfields Bruckhaus Deringer LLP, where he worked on a broad range of significant transactions across multiple sectors and jurisdictions.

Rupert qualified as a solicitor in England & Wales in 2001 and holds a BSc degree in Economics and Politics from Bristol University

Thashmi Doorasamy Group HR & Public Affairs Executive

Thashmi joined Petra in February 2020 as HR and Public Affairs Executive.

Before joining Petra, Thashmi spent 18 years at the Massmart Group, a leading retailer in South Africa. Her pivotal role was HR Director for Massbuild from 2003 to 2013. During this time, Thashmi and her team oversaw the integration of the newly purchased building supply company Builders Warehouse, into the Massmart group. The merger expanded successfully into the wider South African and African market leading to Thashmi’s promotion in 2013, to Group Compliance Officer for Massmart. Later that year Massmart was purchased by the Walmart group. Thashmi led the integration of Massmart’s South African businesses, into the Walmart Group with a focus on compliance. In 2015 she joined the Taste Group, overseeing the People Roll-Out plan for Starbucks.

Thashmi has a B.Admin (Public Finance) with honours in Industrial Psychology from the University of Durban Westville.

Ayoub Mwenda Country and Mine Manager: Tanzania

Ayoub has worked at Williamson Diamond Mine for 27 years in a number of technical and managerial operating roles.

Before joining Petra, Ayoub worked as a Mining Engineer at Chingola and Mufulira Copper Mines in Zambia, before moving to Tanzania as a Mining Engineer at Buckreef Gold Mine. After joined Williamson in 1994 (as a Mining Manager), he was promoted to Production Manager at Williamson, where he supervised both the mining and processing plant. After assuming the role of Assistant General Manager, Ayoub became General Manager in November 2019. Ayoub has overseen the restart of operations at Williamson, following its period of care and maintenance.

Ayoub has a BSc in Mining Engineering from the University of Zambia and is a registered Professional Engineer in Tanzania.


Read more about how our company is governed on the following pages

Board and Company Secretary

Board Committees