The Earth s crust is brittle and can break. Below the crust is the mantle, a dense, hot layer of semi-solid rock approximately 2,900 km thick. It is hotter and denser because temperature and pressure inside the Earth increase with depth. At the center of the Earth lie the core. Its composition is metallic rather than stony, making it nearly twice as dense as the mantle.
Diamonds are one of the crystalline forms of carbon.
They are carried to the surface in volcanic features called kimberlite pipes. To ensure that they are not converted to graphite, diamonds must be transported rapidly to Earth s surface. Methods First we must understand that diamonds are formed at a high temperature and high pressure. In order to create such conditions we use a machine called the Kennedy Press. The diamonds form in these conditions from graphite disks, a weaker structure of carbon atoms.