An Ocean Full of Diamonds

To the diamond industry’s delight, the coasts off Namibia’s shorelines play host to a colossal diamond recovery system. And in contrast to traditional diamond mining, marine recovery is a relatively new deal. 

The Way They Were

Diamonds were first mined in India thousands of years ago. Ancient East Indians often harvested diamonds along alluvial settings by dry or wet riverbeds. Although it’s an historical site now, a few diamonds are still found near Golconda today, but nothing like in its heyday. 

By contrast, marine mining – a much more modern system – began in earnest as recently as the 1960s. 

The Roadmap of Diamond Discovery

When diamonds were discovered in Brazil, a mass migration of prospectors raced to the South American continent. By the 1700s, diamonds discovered there were found mostly in alluvial deposits as well. The independent prospector (garimpero) became the main type of diamond miner. 

Eureka – someone said, referring to the South African diamond stampede of 1867. That discovery produced diamonds, lots of them. Historians speculate that diamond production from South Africa’s first few years surpassed the entire diamond horde from India’s 2,000 year mining history. The crystals coming out of the Cape Colony in South Africa changed the world’s availability of diamond supplies and presented large crystals for imaginative diamond cutters to polish into important diamonds they only dreamt about previously.

The Big Hole

While alluvial diamond panning was taking place, mining in South Africa developed into opening massive holes in the earth. The legendary Kimberley mine is called The Big Hole for that reason. The areas for digging weren’t just helter skelter though. They closely followed geological clues that uncovered diamondiferous (or diamond bearing) soil below the ground.

So By 1869, diamonds were being recovered far from streams or riverbeds. First in yellow earth (later named yellow ground kimberlite) and from areas exhibiting hard igneous rock called blue ground. The tell-tale soil called kimberlite derived its name from the mining town of Kimberley.

Out to Sea

By the mid-1960s, diamond visionaries eager to exploit the diamond producing terrain of South Africa embarked on off-shore mining in the seabeds of the Atlantic Ocean off Namibia. 

It wasn’t that scientists suspected diamonds were under the ocean floor in the same way that they were found underground on dry land. Far from it. These diamonds would have come from elsewhere and found their way out to the seabeds. A brilliant theory – and one eventually proven true.

They already knew the Orange River, the longest river in South Africa ran near legendary diamond mines. So it was pretty straightforward, as geologists believed diamonds washed downstream from the famed Kimberley Diamond mines – a process started millions of years earlier when the Orange River was much larger. They deduced that the Orange River had been emptying into the Atlantic Ocean off Namibia’s shores since virtually forever. That meant diamond-rich materials were also carried along to the Atlantic Ocean with the rest of the river runoff.

Only the Best Survive

Diamond experts say that the Orange River diamonds are of the highest value diamonds in the world, not something every mine can claim. By contrast, a large part of the annual output of other mines is considered to be industrial-use diamonds, and certainly not gemstone quality. 

Diamond recovery vessels the early pioneers developed were adapted and improved upon as they went along. Problems in the early days created challenges to be solved as they persevered. They only recovered a handful of diamonds from the sea floor in the early days, but now, marine diamond mining brings up millions of carats annually.

How They Do It

The ships, called crawlers, are outfitted with 280-ton mechanical arms that shift in a horizontal movement, dredging up material from just below the sea floor, at depths close to 400 feet.

From that dredging, diamonds are sifted out from gravel in a designated treatment area right onboard the ship. The sifted gravel is then returned to the ocean and any recovered gems are securely sealed up and loaded into steel briefcases which are flown by helicopter back to shore. Human hands never touch the diamonds during the entire process at sea.

It’s completely unlike land mining where one can look over specific areas for diamond clues. This recovery takes place some 400 feet below the ocean’s surface. So research is regularly conducted by the mining group Debmarine Namibia which sends out unmanned, autonomous underwater drone-like vehicles to evaluate the seabed with sonar technology.

Debmarine Namibia, the largest offshore diamond prospecting and mining venture is owned jointly by the Government of the Republic of Namibia and De Beers. It is acknowledged the world over for its sophisticated marine mining technology. 

Because this type of diamond mining uproots the seabeds off Namibia, the group is tasked with the responsibility to monitor the seabeds and remedy imbalances that result from the harvesting process. 

Environmental Impact

The waters off Namibia’s shoreline are a key region boasting a high diversity of resident and migratory marine life like seals, sharks, dolphins, and whales. So it’s incumbent upon marine mining to develop plans that mitigate such disruptions. Scientists are already pointing out the multiple stresses upon some species, owing to human related activities like fishing, shipping, and plastic pollutants. So remedial actions are being implemented.

Previously, land mining in Namibia represented the majority of diamond production, but the tables have turned today. Namibia’s Chamber of Mines estimates that marine mining accounts for close to 75% of Namibia’s total diamond production.  And that’s a good thing, says the diamond trade, as scientists project there are 2 more decades of good recovery still ahead of them.