Chemistry of Diamonds
By Julia Galperin
Diamonds really are a girl's best friend, but let's learn about the science behind diamonds. Diamonds can form under high pressure and temperature at meteorite impacts.
The element carbon is important in understanding the chemistry behind diamonds. A neutral carbon atom has six protons and six neutrons in its nucleus. The electron shell configuration of carbon is 1s^2 2s^2 2p^2 (Electron shell configurations show the arrangement of electrons in energy levels around the nucleus).
Diamonds are made up of repeating carbon atoms that are joined to four other carbon atoms through covalent bonds (chemical bonds that involve the sharing of electron pairs). The structure of a diamond is made of 8 atoms that create a cube shape. This is very stable which is why diamonds are hard and have a high melting point (4000 degrees Celcius). The diamond's crystal structure is isometric meaning that the carbon atoms are bonded in the same direction. Diamonds are about 99.95% carbon and 0.05% of trace elements (atoms that aren't part of the diamond's chemistry). Trace elements can influence color or shape.
The presence of trace elements such as nitrogen, sulfur, or boron can color a diamond in shades of yellow, green, and blue. However, trace elements have never been found in pink diamonds. The color in pink diamonds is actually caused by a distortion in the diamond's lattice structure. The distortion causes carbon atoms to shift from their normal positions and alters the light that is reflected by the diamond. Argyle stones are known to have a very intense pink color and this is because they have densely packed graining planes. Pink diamonds are incredibly rare because for every one million carats of diamond producedthere will only be one carat of high quality pink color.