Can someone tell me about this blue marble

[PBR]

Dug this one the other day in a really old area.
I think its glass, but im not certain.
Any ideas as what type or age?
Thanks

 

[cheese]

Cool find! It's an old West Virginia swirl. Sometimes they can be attributed to one maker, sometimes not. This one has Alley traits, so I'd say it was made by Alley, probably early on in their history (1930's). It is glass, just worn down.

 

[PBR]

Thanks Cheese.