SOFTBALL SIZE MARBLE

I recently rediscovered a huge red marble that I had packed away , every time I would come across old marbles in my past thrift store hunting I would purchase them for my boys , eventually they had over 500 marbles of all types and sizes, last year I gave them to my 9 year old grandson, I never knew that certain old marbles had so much value ! I must tell my grandson not to give them away. This is one of the biggest marbles that I have come across ,looks like layers inside with a blotch of white layers almost like a planet, pretty cool !