The Hope Diamond
Diamond is a very stable configuration of carbon. It’s notable physical properties of hardness and thermal conductivity are due to the very strong covalent bonding between the carbon atoms. It crystallizes in a rigid cube called a diamond lattice and when pure is colorless. Impurities cause color: blue, like the Hope Diamond, is caused by boron; the yellow of canary diamonds is caused by nitrogen. In other cases, defects in the crystal lattice can make diamonds appear red, pink, orange or brown. Exposure to Earth’s natural radiation can create green diamonds. And “black” diamonds are not really black, but rather they contain numerous dark inclusions that give them their black appearance.