Clarity refers to the presence of surface or internal flaws within a diamond caused during its formation. If you still have it good you will want to go back and check what the wedding invitation said if anything about the attire. If the wedding invitation is going to take place in the evening on the beach and the invitation has a beach theme to it then you can assume that the attire is less formal.
Explanation of Cut, Color and Clarity of This Diamond
Cut Quality Diamonds with good cut still have very good proportions and will reflect large percentage of incoming light. Good cut diamonds still have excellent brilliance and fire. This grade represents an excellent balance between quality and price.
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 VS1 diamonds have very small inclusions. Usually an experienced grader does not find any internal faults, but does not have great difficulties to see the inclusions when he moves the diamond a little from side to side. Typical inclusions of this group are small, light clouds or small light cracks on the girdle.