(Just to clarify, Glasswipe's photo links are in
Ivo's post, Reply #4 in the other thread)
Cathy, the piece in your first photo is uranium, and that's an accurate photo of the glow? What color is it in daylight? It does seem strange that the whole thing doesn't glow.
I've heard that light emitted by uranium doesn't travel very far through glass (this needs to be confirmed before counting on its accuracy), which would account for the fact that it glows with an intensity not proportional to glass thickness.
I agree that it looks like Ivo's piece isn't stained (and that he'd know what uranium glass looks like). That's interesting that amber uranium pieces don't glow as strongly. Some glass components absorb certain wavelengths of light, iron among them. Iron in sufficient quantities is an amber colorant - I wonder if that is playing a role.
Another photo for comparison. All the pieces are colorless (the one at the top has an amber stain that glows bright orange). The jar on the right is Heisey; almost all clear Heisey glows bright yellowish green due to high manganese levels, and thicker glass is more intense than thinner. The comport on the bottom shows how cut edges of thin glass can glow brightly when the rest hardly glows at all, even when you're not looking through a lot more glass at those edges. Weird optical effect.