I agree with Vitro--nice find!
I have never seen one like it before.
It is an "All Red" made by Vitro Agate imho.
I am not guessing—this one is just one of those that stands out—I know, the green mineral thing that does not mix well—show me another one folks!
“All Reds” are one of the most common marbles made in the USA.
This one is worth 100 times of a common “All Red”.
Thanks for sharing it.
Marble—On!!