金刚石经琢磨后称钻石，自古以来就是最贵重的宝石（如蓝钻石、黑钻石、金钻石等），无色、微蓝和玫瑰色的为上品。金刚石还可用做钻头、切割工具、研磨材料以及高温半导体或尖端工业的原材料。
金刚石是典型的原子晶体，在晶体结构中每个碳原子都以sp3杂化轨道与另四个碳原子形成共价单键(见共价键)，呈正四面体配位，晶格结点间以键能相当大的C—C键相互结合，其键能为345.6KJ/mol，键长为154pm，所有价电子都参与了共价键的形成，晶体内没有自由电子。
透明的金刚石可作宝石(钻石)，价格昂贵，以克拉为其计量单位(1克拉=200毫克)。黑色和不透明的金刚石在工业上用作钻头和切割工具。金刚石粉是优良的磨料。

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.