Diamond Veteran Martyn Charles Marriott Calls for ‘OPEC-Style’ Alliance as Botswana and Angola Seek Greater Stakes in De Beers
As Botswana seeks a larger stake in De Beers and Angola signals similar ambitions, diamond industry veteran Martyn Charles Marriott says this moment could be an opportunity to restore the collaboration and discipline that once defined the global diamond trade.
In a commentary published on the International Diamond Manufacturers website, Marriott cautioned Botswana against pursuing an isolated path that could risk over-dependence on a single resource.
He praised the country’s current deal with De Beers — under which 80% of mine profits go to Botswana — calling it “extraordinary” and unmatched in the global mining sector.
A Call for Renewed Discipline and Cooperation
Marriott believes that ongoing debates about the future of De Beers present a chance to revive the structured systems that once sustained the diamond market — notably the Central Selling Organisation (CSO), which controlled supply and maintained market stability through stockpiling and quota systems.
He reflected on the success of the “Diamonds Are Forever” campaign and the creation of the global diamond engagement ring tradition, both of which cemented consumer confidence and long-term demand.
“Collaboration is what gave diamonds their old strength; fragmentation is what has created their current weakness,” Marriott wrote.
From Botswana to Angola: A Lifetime in Diamonds
Drawing on decades of experience, Marriott recounted his pivotal role in shaping Botswana’s diamond sector. As manager of De Beers Dicor in Sierra Leone, he later advised Botswana from 1970 to 1983, helping establish the joint 50/50 ownership model that remains central to the De Beers–Botswana partnership today.
He also proposed that Botswana’s diamond revenues be used to build a sovereign wealth fund, diversify into tourism, agriculture, and other industries, rather than focusing solely on local diamond processing.
During the 1980s and 1990s, Marriott contributed to rebuilding Angola’s diamond industry as a consultant to Endiama, initially recommending sales by tender — a model that achieved success before being undermined by corruption. He later played an active role in establishing the Kimberley Process, designed to prevent the trade of conflict diamonds.
Fragmentation and the Rise of Competition
Marriott lamented the breakdown of the CSO’s unified approach in the late 1980s when Argyle and De Beers ended cooperation, Russia began marketing independently, and Canadian producers followed suit. The rise of synthetic diamonds, he added, has only intensified competition.
Although no longer active in the industry himself, Marriott’s sons, Luke and Benjamin Marriott, continue his legacy with eValuer, a digital system revolutionizing diamond pricing and valuation.
A Vision for an African Diamond Alliance
Reflecting on current developments, Marriott proposed that African diamond producers — led by Botswana and Angola — consider forming a coordinated alliance, similar to OPEC, to manage supply, stabilize prices, and ensure sustainable growth.
“Times change,” he wrote. “Botswana is seeking a greater interest in De Beers, and Angola is seeking an interest too. To my mind, this could be an opportunity to return to old strengths and disciplines — some sort of OPEC for diamonds that could provide a basis for the future.”
