If you know somebody who is allergic to wool - and they are willing - they
could hold it and see if it triggers a reaction.
Otherwise, microscope. You can buy pretty good microscopes these days,
including some that plug into a computer via USB so you can capture images.
Wool is scaly like hair, syn
If the reason you need to know is to figure out how to wash it, you could
simply plan to hand wash it to be on the safe side. Baby things are small and
usually don't take forever to wash or dry.
If there are other concerns (such as potential allergy), the smell and feel
tests should give you a