you throw to the ground it bounces it bounce ball, if no bounce is gumchewball will get cracks .and hair .
if put in mouth if sugar taste and easy chew is gumchewball. will make rubber bubble if brethen threw. if put in mouth and hard chew but go back to ball with dust on it. then bounce ball.
after a while, trapped in that dome, all of them will smell like rubber... the trick is to look for the melt seam... the rubber balls start in two halves and get melted together... gumballs don't have that...