Diamond Mining & Exploration: Where it all starts
Diamond mining: Surveying a potential mine for diamonds is called diamond exploration while the process of actually obtaining the rock is called diamond mining.
Your diamond engagement ring, your lovely pair of diamond earrings or diamond bracelet have one thing in common; diamonds. At some point, you may have wondered where these came from. Their authenticity and origin might have been a question at the back of your head.
Yes, we all know about diamonds forming in the depths of the Earth and coming up towards the surface through volcanic eruptions. Do we know anything else? Maybe or maybe not. But there’s no harm in finding out.
Let’s see how
Since diamonds are formed only under extreme heat and pressure, their formation begins in the Earth’s mantle. Later, it takes an act of Nature, (a volcanic eruption in this case) to bring them closer to the Earth’s surface.
This is where geologists test and find out which rocks could possibly be holding a rough diamond.
So, these volcanic eruptions (sometimes really violent ones) create lamproite and kimberlite pipes. They are channel-like openings starting from inside the Earth and leading up to the surface.
This is the place where miners find diamonds in their crudest form, inside the kimberlite rocks. However, this is not always the case; every kimberlite is not necessarily home to a diamond.
Surveying a location for diamonds is called diamond exploration. The process of actually obtaining the stone is called diamond mining. The exploration of diamonds is carried out in two phases: initial and advanced.
Types of diamond exploration: Initial exploration
In the first type of exploration, there are five ways to conduct a survey. They are geophysical and geochemical surveys, geological mapping, drilling and trenching.
Geophysical surveys use electromagnetic, electrical and gravity techniques to find information about ground-based exploration. After this step, diamond mining companies use mapping and sampling to study in the location.
Diamond drilling involves retrieving core samples which then undergo chemical analysis. Trenching involves bulk sampling of ores closer to the surface.
If the initial exploration is successful, then the advanced exploration follows. Bulk sampling and extensive drilling are also used in this kind of exploration. Its purpose is to get useful information about the rock quality and geochemistry (chemical composition of the earth and its minerals).
It is necessary to assess the distribution of tiny diamonds along with their size and frequency at the time of advanced exploration. The type of research is called microdiamond analysis.
To understand the approximate grade or revenue of diamonds, macrodiamond analysis is done. During this type of analysis, kimberlites that are over 100 tonnes are bulk sampled.
Beyond the process
There is more to diamond mining and exploration than just the techniques and processes. These processes help locate the mines because every location does not necessarily contain diamonds.
To begin mining without first studying the area will mean a waste of time and resources. Sometimes certain mines close due to several reasons while a new one could be discovered in another location. It then takes a while to locate the new one and study it.