Lorena Jenkins
Editor and Dancer in Maple Shade, NJ
Diamond, a mineral composed of pure carbon. It is the hardest naturally occurring substance known; it is also the most popular gemstone. Because of their extreme hardness, diamonds have a number of important industrial applications. Diamonds are expensive because they cost a lot to bring to market, there's a limited supply of fine quality gems, and people around the world want to buy them. It's simply supply and demand.