Elena

Thank you very much for help. 

Thanks for the reply! It's 1.5 inches in diameter, and here are some better pictures showing the pontil mark up close.

I don't know anything about marbles, but I bought this (along with a few other) marbles at the thrift store and after doing a little research realized it may be hand-made as it has a pontil mark.  Can anyone tell me any more information about it?