The order is from best to least in quality..solid gold, gold filled , and gold plated. Gold filled is always a good buy . Its sturdy like gold, it shines like gold , and it wont dis color your skin like gold plating. Its the best of both worlds. Respectable pricing with pure gold benefits. There are other metals mixed in in the inner layers like silver and rhodium. Real gold is then layered on the outside of the metal mixture. That is why the gold doesn't wear off or discolor your skinny skin skin :-)