A mined, natural diamond is a crystallized carbon structure that is formed beneath the earth's surface over millions (or sometimes billions) of years under the perfect conditions of heat and pressure. The diamonds are brought to the surface during natural events (like volcanic eruptions) and then mined from the land.

Are diamonds made from coal?

Over the years it has been said that diamonds formed from the metamorphism of coal. According to Geology.com, we now know this is untrue. “Coal has rarely played a role in the formation of diamonds. ... The diamonds form from pure carbon in the mantle under extreme heat and pressure.

How long does it take for a diamond to form?

That is miles upon miles between the earth's surface. Due to the immense pressure that is present in this part of the earth, as well as the extreme temperatures, a diamond gradually begins to form. The entire process takes between 1 billion and 3.3 billion years, which is approximately 25% to 75% of our earth's age.