Help with identifying marbles

[bottlerocket]

I have been finding marbles while bottle digging and have a few to show and see if I can get info on.
3 look to be glass and one is all white.
The 5th one does not look "glassy", Maybe Agate?
Thanks

 

[Road Dog]

middle marble looks handgathered. Probably M. F. Christensen Slag. Need to see North and South poles to be sure.

 

[bottlerocket]

Thanks Road Dog,
Here are a couple more views

 

[bottlerocket]

And another

 

[Road Dog]

M.F. Christensen

 

[bottlerocket]

Thank you.
Is it rare or common?

 

[Road Dog]

In that size fairly common. Marble is near a hundred years old though.

 

[bottlerocket]

Thanks Road Dog, that was my next question.