Definition of COMMODITY RATE. : a common carrier rate distinguished from a class rate and applicable only to a specific commodity or group of related commodities carried between specific points or territories. ADVERTISEMENT. a common carrier rate distinguished from a class rate and applicable only to a specific commodity or group of related commodities carried between specific points or territories.
Cubic Zirconia. Cubic zirconia (CZ), a diamond simulant, is not only the oldest diamond substitute, but also the most popular. Composed of zirconium oxide (ZrO 2) the mineral is extremely rare in natural form. Discovered by German mineralogists in 1937, zirconium wasnât considered economically feasible.ubic zirconia possesses less brilliance (less sparkle), but has more fire (flashes of rainbow color.) CZ is also very hard, not quite as hard as a diamond, but like a diamond can scratch glass.
In each form, the coordination geometry at Zn and S is tetrahedral. The more stable cubic form is known also as zinc blende or sphalerite. The hexagonal form is known as the mineral wurtzite, although it also can be produced synthetically. The transition from the sphalerite form to the wurtzite form occurs at around 1020 Â°C.