How many diamonds are on Earth?

Could you elaborate on the vastness of the question "How many diamonds are on Earth?" Is it referring to the total number of diamonds that have been mined throughout history, or is it attempting to quantify the total amount of diamonds that exist naturally within the Earth's crust? Considering the difficulty in accurately assessing the abundance of these precious gems deep within the ground, how do scientists and experts estimate their numbers? Additionally, are there any factors that could influence the availability of diamonds, such as geological processes or human intervention?