I just want to clarify something. I am not saying this marble isn't Vitro, I have not seen them all. In fact, I would say that if this marble is American it's likely a Vitro - I couldn't imagine who else would have made it. On the other hand, it would be a very unusual Vitro, IMO. I'm pretty sure I have a few that would fit nicely with these in my Vitro archive, maybe with different colors too, but I'm not certain. Unfortunately, I'm not close to my collection at the moment.
The colors on certain marbles I have in my Vitro archives has always bothered me a bit - I have to work pretty hard to convince myself that they really are Vitro colors. Beyond that, the marbles look Vitro enough that they're in there. Lately, I have been looking at El Aguilas production and I notice that some of them share similar colors and combinations to some of the interesting ones in my archive, and I think I may have figured out a way to sort out the interlopers. But that idea is not ready for prime time yet.
I have had many of these marbles for many years, probably long before I ever even heard of El Aguila, and certainly way before I had access to verified examples of their production. And at this point, I'd be kind of surprised if I didn't have 50 of them in there, and I plan to have fun trying to sort them out.
🙂