That is a small one! Can you get closer pics with more light? It's hard to tell much about it. Is it glass or does it appear to be glazed pottery? Looks like maybe it could be a bennington.
Please forgive the intrusion. But, I have a question. So I should not automatically dismiss all really small found marbles as all being made for Chinese checker sets ?
No. Chinese checkers marbles are usually smaller and solid colored. If they are small and swirled or more than one color, they probably aren't chinese checkers marbles.