The large egg is a chicken's egg, of course, but the small egg is a quail's egg. One of the volunteers brought five of them to me today because she knows I like to blow out eggs and decorate them. I've never had quail eggs before but I thought it would be the same. Well, the shells were quite fragile. I managed to end up with two nicely done quail shells and three totally messed up shells.
I don't think I was at fault. The quails need more calcium in their diet for stronger shells. If they just want to eat the tiny little eggs, the shells probably aren't an issue.