Diamond after pondering, known as the diamond, since ancient times is the most precious gems such as the blue diamond, black diamond, gold, diamonds and other, colorless, bluish and rose for the top grade. Diamond can also be used to do drill, cutting tools, grinding materials, as well as high temperature semiconductor or cutting edge industry.
Diamond is a typical atomic crystal, in the crystal structure of each carbon atom are to SP3 hybrid orbitals and the other four carbon atoms form covalent bond (see covalent bond) and positive tetrahedral coordination and lattice nodes to bond to considerable C C bond with each other. The key to for 345.6KJ/ (mol / mol, the bond length of 154pm, all valence electrons are involved in the formation of a covalent bond and crystal no free electrons.
Transparent diamond can be used as a gem (Zuan Shi), the price is expensive, the carat is its measurement unit (1 carat =200 mg). Black and opaque diamond used in industry as a drill and cutting tool. Diamond powder is an excellent abrasive.