Like a diamond, cubic zirconia also uses a grading system to separate the lowest from the highest quality. The grading system is the same as that of diamonds and other gemstones. They use the Four Cs to clearly outline the quality (color, clarity, cut, and carat weight). However, for the CZ, the grading system is a little different:
The quality of CZ manufacturers varies; some are less acceptable than others, and clarity is the characteristic that may change. When determining the quality of the cubic zirconia characteristics, a five-tiered system of A(1A) being the lowest grade, and AAAAA(5A), representing the highest grade, is used.