Plutonium ? Radioactive ?

[newmarblemom]

OK guys ! When exactly were you planning on telling me about these ? 

My son recently became facinated with black lights so I got him a little black light flashlight. Imagine my sunrise when he walked into my dark bedroom last night and my marble corner lit up like an airport ! Any ideas on these fluorescent guys ?

[Parmcat]

Marbles that glow green have uranium glass in them.  It's not uncommon, and a lot of modern makers still use it.  I used to think it meant the marble must be old, but that's not the case.

If they glow orange that is cadmium glass

I still check all my marbles and enjoy the glowers