In response to polite inquiries received at this department allow me to say: I do not know how neodymium is used to produce bright purple glass. I assume that it is put into the glass somehow to either create the purple or the brightness. Possibly both. But wouldn’t it be just like the rare-earth metals for the key to be taking out the neodymium as part of the glass-making process? Anyway all I know is that if you want bright purple glass, one thing you can look for is neodymium. I’m afraid past that you’re on your own.