There is a signature of some sort on the inside Will fit a 5-6 18K HGE" on a piece of jewelry means that it is electroplated with 18 karat gold and the gold plating is slightly thicker than a piece marked "18K GP" or "18K GE". "HGE" can stand for "High Grade Electroplate" or "Heavy Gold Electroplate". Plated jewelry has a thin layer of gold over a base metal that is not gold. Some plated jewelry may have markings that make it look like solid gold.