Not the most exciting marbles but a little interesting. Makers?

[The Nickel Guy]

These are a notch better than your ordinary game marbles I suppose. The white ones glow brightly under UV light and have traces of blue, the green ones have a noticeable amount of aventurine. That 1st green one in the second row left is a reflection in the AV and not white furnace brick or other. The black ones have some sparkles but they are very tiny. The black ones also look quite swirled under a black light. Thank you very much.

[Roberto]

That first green marble you mention seems to be a metallic inclusion, not aventurine, (even though I can't see it clearly)

What size?  Possible Champion