If you have recently been looking at engagement rings or speaking to custom jewelers about custom engagement rings you may be wondering where diamonds come from and how do they form. The first diamond discovered was in the 4th century B.C. in India. A lot of people think that diamonds form from coal, but this is actually not true. There are actually four ways that form most diamonds. The first way diamonds form is in the mantle of the earth. Then some sort of volcanic eruption brought these diamonds from the mantle to the earth’s surface. There has actually not been a time that scientists have witnessed this but this is their theory on how diamonds have come to be. Diamonds eroded and weathered from this are found in sedimentary deposits. In order for a diamond to form they need a lot of pressure and very high temperatures. This can only happen within the mantle of the earth. The temperatures are around 2000 degrees Fahrenheit. There is nowhere else in earth where these conditions exist. This is where we get most of the commercial diamonds. The second way diamonds form is in subduction zones. There are some rocks that have diamonds in them that have been subducted into the mantle and then brought back to the surface. These diamonds do not go as deep into the mantle and they do not get as hot. There are some diamonds that have contained ocean crust so they think that subducted seawater was part of their formation. However, diamonds that have been discovered like this are not very big and therefore have not been used commercially. The third way diamonds form is from asteroid impacts. When an asteroid hits earth there is very high temperatures and pressures involved. Therefore when it hits earth the conditions are perfect for a diamond to form. The reason why this theory exists is because there have been diamonds found around places where asteroids have hit. There are meteor crater sites in the US and Russia where diamonds have been found. The fourth way diamonds are formed is in space. Researchers have discovered diamonds in some meteorites. The diamonds found in these meteorites are very small and not able to be used commercially. They think these diamonds formed because of an asteroid impact. The four natural ways diamonds are formed are from pressures and temperatures in the mantle and subduction zones, asteroid impacts, and in space. The reason why researchers believe coal did not form diamonds is because coal is formed from plants. And diamonds date back much earlier than plants, therefore coal could not have formed diamonds. After people learned how diamonds formed naturally they started to mimic the process to make fake diamonds. The first man-made diamond was done in 1954. They applied force and high temperatures to diamond seeds. This process takes around 28 days. So, when you are looking for a diamond, make sure that you are choosing the best quality and remember where they came from.