Diamonds

Abstract

Although natural diamonds are found on the surface of the earth, they did not originate there. They grew in the depths of the earth under conditions of high temperature and high pressure and were subsequently extruded to the surface. This complicated temperature and pressure history results in particular types of defect being present in natural diamonds. This article describes the various types of defect as well as a number of physical properties of diamond. The synthesis of diamond is also described. It is hoped that information about natural diamonds will give some insight into their conditions of growth and their subsequent extrusion to the surface.