Production of Diamonds.
The diamond is the hardest natural substance known. It is found in a type of igneous rock known as kimberlite. A igneous rock is formed through the cooling and solidification of magma or lava. The diamond is essentially a chain of carbon atoms that have crystallized. Diamonds started to form inside the earth 3.3 billion years ago due to extreme heat and pressure.
This map shows where diamonds are mined around the world.
As you can see in this map it shows the main diamond producers around the world such as Russia, Canada, Sierra Leone, Angola, DR Congo, Botswana, Namibia, South Africa and Australia.