Hi. Welcome.
My brain is mush today but I wanted to say hi.
The bottom row looks like West Virginia swirls.
The top left ... that pattern looks like the "horseshoe" shape of some Vitro cat's eyes, but my brain isn't making sense of the color distribution between the ribbons.
I agree a good chance of Jabo based on both size and pattern.
That would put it after 1990.
With an Alley (the most likely older candidate for a 1" marble) the swirl pattern would tend to be crisper. It would be easier to see what color was the ribbon and what color was the base.
Robwell, what led you to think it would be old?
The crease you're showing in the first two photos is called a "cold roll". The marble was just a little bit too cool to for the molten glass to be completely smoothed out on its ride down the rollers.
Right about the name slag. The typical manufacturer term for slags was "onyx".
"Onyx" became a problematic name in the early 30's if I recall correctly -- because the true mineral onyx industry was trying to get protections against glass makers presenting their products as onyx -- but by then marble makers were mostly switched over to non-slags. Hmmm ... now I start an argument in my head about how Akro continued to use the name "onyx" into its corkscrew-making days well into the 1930's ... but I refuse to delete because most of what I said above is still true ... I think. lol
The defendant in the FTC case was Gropper and the order to be very clear about what was meant by "onyx" applied to the Peltier marbles which Gropper was selling. https://books.google.com/books?id=y17ilneaDCAC&pg=PA274
Vitro Helmet on the bottom left. Green and yellow looks Peltish to me (upper right quadrant).
Several Akro corks, some Pelt Rainbos, other Vitros, a Master brushed patch.
I would assume set. But I gotta leave it to one of the Jabo experts to say whether it all came from a single run and, if so, which run.
I'm not recognizing it as the first Joker's but that was a long time ago and I wasn't as interested in Jokers as I was in Tributes.
Oy. At 1" that's a tough call. Could be a later (estimate 1950's) Master. The colors seem to be in the right general area. The orange peel is making me wonder if it might be European.