The glass has internal stripes no doubt uranium glass. This glows beautifully in the dark. There is a 1 inch long raised trail of glass inside the font. Definately occuring during the manufacturing process on the top which i have shown a photo of. The font fitter has i think beencovered with a soldering metal hence covering the thread.This item is in the category "Collectables\Lamps, Lighting\Lamps". The seller is "sindy1955" and is located in this country: GB. This item can be shipped to North, South, or Latin America, all countries in Europe, all countries in continental Asia, Australia.