I always thought stud earrings were the highest grade - that's why the gem strands are also known as loose pearl earring grade. My understanding is also that if a necklace is stated as AAA then it should be an AAA strand, but the size graduation may be a bit different than a bracelet because of the length. I would expect earrings, pendants and rings to be made with higher grades (apart from flaws concealed by setting) as they are more isolated. But I'm not a jeweller and I don't make any accessories myself, so I could be wrong.
Aspiring ninja. Go Storm Shadow!