Allotropes of carbon dispersion of light of diamond make it useful for both industrial applications and jewelry. Diamond is the hardest known natural mineral. This makes it an excellent abrasive and makes it hold polish and luster extremely well. No known naturally occurring substance can cut (or even scratch) a diamond, except another diamond. The market for industrial-grade diamonds operates much differently from its gem-grade counterpart. Industrial diamonds are valued mostly for their hardness and heat conductivity, making many of the gemological characteristics of diamond, including clarity and color, mostly irrelevant. This helps explain why 80% of mined diamonds (equal to about 100
Amount of substance replaces the term "number of moles" which should no longer be used according to IUPAC recommendation. However, confusion can arise due to the everyday usage of the term amount and the term "enplethy" has been suggested for international usage to replace amount of substance. When amount of substance enters into a derived quantity, it is usually as the denominator: such quantities are known as molar quantities. For example, the quantity which describes the volume occupied by a given amount of substance is called the molar volume, while the quantity which describes the mass of a given amount of substance is