Material properties of diamond to a very large kinetic energy barrier, diamonds are metastable; they will not decay into graphite under normal conditions. Material properties of diamond Diamond is the allotrope of carbon in which the carbon atoms are arranged in the specific type of cubic lattice called diamond cubic. Diamond is an optically isotropic crystal that is transparent to opaque. Diamond is the hardest naturally occurring material known. Yet, due to important structural weaknesses, diamond's toughness is only fair to good. The precise tensile strength of diamond is unknown, however strength up to 60 GPa has been observed, and it could be as
Diamond cut the original shape of the rough stone, location of internal flaws or "inclusions", the preservation of carat weight, and popularity of certain shapes among consumers. The cutter must consider each of these variables before proceeding. Most gem-quality diamond crystals are octahedra in their rough state (see material properties of diamond). These crystals are usually cut into "round brilliants" because it is possible to cut two such stones out of one octahedron with minimal loss of weight. If the crystal is malformed or twinned, or if inclusions are present at inopportune locations, the diamond is more likely to receive a "fancy