Your beloved 14k diamond ring, for instance, would definitely stand out at a private funeral.
When at work, you do not want to be wearing jewelry that makes noise as you move. Coworkers at even the most progressively oriented offices can take to this badly, because it gets plain annoying after a while, assuming it does not right off the bat. Moreover, avoid statement diamond pieces that could prove a distraction to others.
If you decide to wear an over-sized piece to a formal event, draw the line at that. Ideally, you end up drawing attention to a single part of your body, which is what over-sized jewelry is for. Make sure what you pick for the day goes well with your hair, outfit, and makeup, as well as the occasion. A Y-shaped necklace, for instance, would suit a low cut dress exceptionally well.