Oh and if you want to see some beautiful insects look for jewel bugs. Another thing that I thought about are tiny bones like mice skulls. There are so many lovely seed pods worth looking in to as well. And fern makes lovely shapes. Ha! I really like jewelry inspired by small details in nature.
I love bugs in general and is always happy to see them in jewelry. I especially like almost any kind of beetle. I like also like flies, snails, dragonflies and the plainer kinds of moths. I would never wear day butterflies though or ladybugs, those are to cute. Spiders are pretty but I feel like I'm dressing up for halloween with those as jewelry. I really like the acorn idea. Perhaps you could put some of the bugs on leaves? Oak leaves are particulary pretty.
Yes, snail shells would make great jewelry! Especially if they had some nice colors on them... with the spiral, they would be fun to stare at. XD I also like the idea of luna moths. They have such interesting wings.
I personally really like those bright blue butterflies with the iridescent wings. I don't normally wear jewelry but I would love to see some with that kind of butterfly on it.