I am not an expert, so anyone feel free to correct me:
1) Vegetarians probably don't do leather, but are likely OK with the others - if the creation of the product requires the death of an animal, it's pretty much a no-go for both vegans and vegetarians, but vegetarians may use products (like wool or eggs) that come from an animal but don't require the animal's death.
2) Vegans generally don't use any products that require the exploitation of animals - eggs, milk, honey. I don't know if that goes for wool, but most likely applies to pearls.