Diamonds are found in many colors and shades. They acquire a color depending on the kind of impurities that may bond within the carbon lattice comprising the diamond. While impurity in the form of boron gives them a gray or blue color, nitrogen imparts them brown or yellow color. The process of irradiation causes them to acquire shades of green.
Natural Diamond Coloring
Natural diamonds get formed under extremely high pressures and temperatures. Since these are formed very deep in earth, impurities tend to seep thru and get mixed with the carbon content of diamond. Varying degrees of heat and pressure during the natural formation of diamonds causes them to have varying colors.
Artificial Diamond Coloring
Just like crystals, diamonds too can be produced in lab. The basic conditions for making such diamonds remain the same, extremely high pressure and temperature. Creation of such environs needs high-pressure presses, and even explosions are created to get artificial diamonds.
Just as in case of crystals, diamonds too may be grown using some chemical processes. Chemical process facilitates controlling chemical impurities incorporated during the growth of diamond. This process allows having synthetic diamonds in almost any color of natural diamonds.