Same here, some of my silvers glow and some don't. Although the base glass looks identical. All ade reacts to UV, lemonade, limeade, cherryade, blueberry ade. My suspicion is the silver oxbloods are just made from a different batch of glass that had Uranium in it, thus the reaction. I don't believe I've ever seen an egg yolk ox that reacted. ?? But there is an exception to every rule especially when talking about marbles, somebody probably has an egg yolk ox that reacts. The silvers that do react tend to be worth a tad more $$ since it is a rare occurrence. Agree, Never had a milky that reacted either.