Diamond is a previous stone. It is crystalline form of pure carbon. Diamond is the hardest naturally occurring substance on earth. It has an octahedral crystal habit and a density of 3.51gcm3.
Russia and Botswana are the largest diamond producers in the world.
Russia has the biggest diamond mines in the world. Russia is also rated the world's greatest exporter of rough diamonds. Democratic Republic of Congo is also a prominent producer of diamonds in the world.