I love a good UV glow.
I tried for years to finish a row of ten in a 100-count box of Akro "Prizenames", they were just basic yellow and--not quite white. (these are quite hard to find actually)
You will be amazed at all the different glass that Akro used and included in these simple-looking marbles.
UV light spoke to me then and helped to get a good row that is consistent. It took some time but this is collecting-nuff said.
Backlighting and UV light are valuable tools to include in your arsenal—also a good bright pen light light and someway to see closer—I use magnified spectacles—just because.
These bigger ones never act like the smaller ones and visa versa--the tiny ones have a mind of their own as well.
Marble—On!!