An item with the stamp 18k HGE is gold plated with 18-karat gold. HGE is an abbreviation for "heavy gold electroplated," meaning that a very thin layer of gold has been added to an item to give the item the appearance of gold without any value.
An item consisting of only gold contains a stamp indicating the karat number. A gold filled item consists of a gold plating made of at least 10-karat gold at 1/20 of its total weight. The abbreviation G.F. indicates "gold filled." Heavy gold electroplating is a technique that allows for gold plating with the minimal amount of gold, measured by a thousandth of an inch.