A ring that is marked "18KGE" is made of an unspecified metal that is electroplated with a thin layer of 18 karat gold. This electroplated layer differs from other gold covering in that the gold has been electrolytically deposited in a uniform manner.
Federal standards mandate that, in order to be labelled as gold electroplate, the gold must be at least seven millionths of an inch thick with a purity of at least 10K. Items that are thinner than this amount are generally labelled, "layered in 14K gold," although gold tone and gold wash are federally approved terms. Items with a thickness of 100 millionths of an inch are marked with "HGE," meaning heavy gold electroplate.