This is because moissanite is a lab-created imitation diamond. Your jewelry may be completely clean, or may have a white powder on its surface from the oxidization. Remember to exercise caution in cleaning silver jewelry.
Explanation of Cut, Color and Clarity of This Diamond
Cut Quality Diamonds of fair cut quality are still quite attractive, but they may not be as brilliant as the top 3 grades. Fair cut diamonds are proportioned to yield more carat weight from the diamond rough. Such diamonds may be attractive to budget-conscious customers.
Color Diamonds of F color are very close to colorless. Very small percentage of natural diamonds fall into this category. Even a trained professional will not be able to detect presence of color without instrumentation.
Clarity The stones of SI2 clarity have inclusions which are fairly easy to see under a loupe with 10X power magnification. Such inclusions may be visible to an unaided eye depending on their location. SI2 clarity diamonds of G or H color look nearly perfect when mounted. For those looking for near perfection these sure come close.