Unintentional Aventurine is always a thing in any green color from any marble maker from around the entire planet.
It is a common thing to find in any marble that includes the color green—even Akro.
It has to do with the glass recipe in some shape or form or use.
@Alan more than likely has a better explaination of this and I hope that he chimes in.
Saying that, some Akroware had some intense UV in the green colors that had to be intentional imho.
Some of those two tab ashtrays just light up with it.
Marble—On!!