The 1 carat diamond stud earrings are usually considered the perfect earring. There is no specific reason as to why, but in general, it's is accepted as such. It's probably because a 1 carat stud earring is the perfect size to sit on the earlobe. It's big enough to catch the light and sparkle, but no so big that it looks gaudy. There are a few other things to consider when buying your "perfect" 1 carat studs.