There are four main things we usually associate diamonds to when we see or hear about them. First, we think of how astonishing they would look on our partner’s fingers. Next, we all know diamonds are the hardest substance on Earth even though many of us have a misconception that they are unbreakable (in truth they are!).
Also, some of us can relate to the industrial uses of diamonds as super heat sinks or drilling parts. And finally, most of us probably stereotype them with the high price tags pegged to diamond jewelry. Together, these four things may seem like they cover everything related to diamonds or do they not?
When was the last time you thought about the African people and miners who are getting their hands dirty in order for you to wear that beautiful engagement ring? As it turns out, mining for diamonds is one of the most resource-heavy and time-consuming processes that companies have to invest their efforts in.
Even with all our technological advances and engineering tools, diamond mining still incorporates a certain level of art and science combined. So, let us also take a look at some methods in which rough diamonds are extracted from the ground.
Here is a list of topics we will be covering:
The Mir open-pit mine (“World” or “Peace”) in Russian city, Mirny.
Before any actual mining even takes place, prospectors need to locate the diamond sources first. Geologists do this by following the trail of secondary diamond sources (e.g. river beds) to determine where the primary sources of pipe deposits are.
Once the pipes are found, ore samples are examined to evaluate suitability and profitability in mining. If the presence of diamonds is proven true and profitable, shanks are inserted into the ground at the ore-bearing pipes and huge amounts of soil are extracted.
To make mining efficient and effective, the raw rock and soil are typically not examined on-site. Instead, they are transported to special plants where the ore is processed and the rough diamonds are extracted. Depending on how rich the ore is, a few hundred tons of ore might be sieved just to produce a single carat of gem quality rough diamonds.
Even after extraction, the rough diamond is still far from being set in an engagement ring. In heavily secured facilities, rough stones are sorted into various gem-quality categories and industrial-specific grades. Thereafter, the roughs are sold, cut, polished and commercialized.
As you can imagine, the journey a rough diamond undergoes from its violent formation process to being mounted on an exquisite setting is a long process and passes through many different channels.
Alluvial mining processing plant.
Throughout the course of history, the Earth’s landscape had been constantly changing. Water, streams and rivers are the main drivers in the formation of secondary mining deposits as they can transport rough diamonds away from Kimberlite pipes to locations as far out as the ocean.
Another mining method that is frequently used is called alluvial mining. This type of mining is usually performed in areas of secondary deposits like riverbanks, beaches or even off-shore locations.
Alluvial mining involves the building of walls and the diversion of rivers. Once the water is emptied out and prevented from flowing into the area of interest, bulldozers are then used to exploit the ground of the riverbank.
Usually, kimberlite ore can be found in depths of at least 15 meters. When the diamond-rich depth is reached, the raw material extracted from the ground is then transported to a special screening plant for further processing.
There’s another form of alluvial mining called artisanal mining. In essence, it is basically the same method employed by gold diggers which involves the screening and straining of mud.
In the case of artisanal mining, the extraction process usually takes a longer time as it involves low tech equipment and manual labor. Compared to alluvial mining, the post-processing is shorter and is a less resource-consuming task as diamonds are identified in situ of the work area.
Coastal ships fitted with vacuum suction tubes for marine mining.
Deposits of diamonds found in marine bodies are a result of kimberlite pipe erosion. When heavy rain occurs, the exposed diamonds are washed into rivers and carried towards the coast.
Namibia is a country that holds the biggest quantity of gem quality marine deposits in the world. Currently, the country has a partnership with De Beers to conduct marine-based recovery and it has produced more volume than land based mining.
Because marine deposits are distributed over large areas unevenly, mining companies utilize different methods to mine them. Some of these methods include shallow-water mining, deep sea operations involving high tech equipment and simple alluvial mining.
Did you know that alluvial mining can cause serious deterioration and damage to our natural environment? You might have heard of the Big Hole (the Kimberley open mine) or the Jagersfontein Mine where some of the most famous diamonds in history had been unearthed.
Unknown to many people, these mines are the biggest man-made holes and had also left permanent scars on our planet’s surface which could be seen from space.
Largest man-made hole on Earth – The Kimberly open pit mine