A person who practices lapidary is known as a lapidarist. A lapidarist uses the lapidary techniques of cutting, grinding, and polishing.
Diamond is the hardest known material. It provides a standard against which other materials are compared to. As such, it is the longest wearing surface of any material. Diamond's extremely high thermal conductivity removes heat from the cutting edge also helps to extend life.
Diamond excels in "hardness" and "heat diffusibility" as a cutting tool material. CBN, with hardness akin to that of diamond diamond is mainly used for cutting ferrous metal thanks to its lower reactivity than diamond with ferrous metal. Both materials can be polished to form "sharp cutting edge."
Advantages. Diamond is one of the hardest natural materials on earth; much harder than corundum and silicon carbide. Diamond also has high strength, good wear resistance, and a low friction coefficient. So when used as an abrasive, it has many obvious advantages over many other common abrasives