I picked this up at a local estate sale and I find it fascinating. It probably used whale oil. It seems to be hand forged and made from cast iron. There is a marking of crossed miners picks with the gluck auf above it. The item "Antique Gluck Auf Coal MINERS FROG OIL LAMP" is in sale since Thursday, January 2, 2014. This item is in the category "Collectibles\Rocks, Fossils & Minerals\Crystals & Mineral Specimens\Decorator Pieces".
The seller is "wfw06897" and is located in Wilton, Connecticut. This item can be shipped worldwide.