Share 'Unusual painted glass lamp shade'

I wonder if anyone is familiar with this type of lamp shade. It is blown, white glass, painted on the outside in a rather primitive style, 8 3/4 inches in diameter with a 3 inch opening at the top. The opening has a metal ring which is tarnished and perhaps nickel plated. The lower edge of the shade is polished, not ground. It is light in weight. My assumption is that it is for a kerosene lamp, o…