Diamonds are found underground primarily within specific geological structures that transport them from deep within the Earth closer to the surface.
Deep beneath our feet, diamonds crystallize under immense pressure and heat in the Earth's mantle, hundreds of kilometers down. However, these precious gems aren't typically mined directly from the mantle. Instead, nature has a dynamic process that brings them within reach.
Volcanic activity plays a crucial role in bringing diamonds closer to the surface. Explosive volcanic eruptions can create conduits that act like express elevators from the mantle upwards.
The Primary Locations: Kimberlite and Lamproite Pipes
Generally, diamonds are taken from lamproite and kimberlite pipes. These are specific types of volcanic conduits that were responsible for transporting diamonds from the depths of the Earth's mantle to the surface.
- Kimberlite Pipes: Named after the town of Kimberley in South Africa, these are the most common source of mined diamonds. They are carrot-shaped or cylindrical structures formed by violent, deep-source eruptions.
- Lamproite Pipes: Similar to kimberlites but less common, these volcanic pipes also originate deep within the mantle and can carry diamonds.
So, when we talk about finding diamonds underground, we are essentially talking about locating and accessing these ancient kimberlite and lamproite pipes. The diamonds are embedded within the rock that fills these pipes.
Extracting Diamonds from Underground Deposits
Once these diamond-bearing pipes are located, various mining methods are employed to extract the diamonds embedded within the pipe material. According to sources, there are numerous ways of extracting diamonds from these pipes, including:
- Open-Pit Mining: Removing layers of earth and rock from the surface downwards to access the pipe.
- Underground Mining: Creating tunnels and shafts to reach deeper parts of the pipe below the surface.
- Marine Mining: (Relevant when pipes or alluvial deposits extend under the sea).
- Alluvial Mining: (Extracting diamonds that have been eroded from pipes over millennia and transported by rivers or glaciers).
Therefore, diamonds are found underground by locating these ancient volcanic pipes, which serve as the primary source rocks where the diamonds reside after being transported from the Earth's mantle. Extraction follows the discovery and geological mapping of these pipe structures.