Sounds like it could do the job. Maybe a great piece of jewelry. You have to ask these questions. Time of the year has a lot to do with this, also where you live. If someone goes to too many earrings at a fairly young age, they may regret it when they get older.
Employers tend to frown upon that look.
If you want to wear multiple earrings, use the clip kind. The term business casual has basically lost it's meaning as far as I can tell. Some places it means khakis and shirt. Just write what you want and don't worry about an all-compassing term. As far as I heard, it will be an evening wedding and fairly traditional.