I find it impossible just by looking with the naked eye, if a chain is gold filled or it is gold plated. You can tell after wearing it for a while (a few weeks to a few months later), when gold plating tarnishes or the plating has started to wear off. Gold filled performs the same as solid gold under normal wear and tear. However, there is a faster way to test real and fake gold filled – a gold acid test. In this video, I am showing how it works
You can detect solid gold by using a gold testing machine. The machine is not useful in distinguishing gold filled from gold plated. The gold acid scratch test allows you to test the surface gold and its karat content. There are different tests for different karat: 10k, 12k, 14k, 18k and 22k. Most of the test kits come with a scratching stone, which is abrasive.
The kit is useful to test real or fake gold filled. Simply rub the chain or component against the stone . The surface layer of the test component will leave markings on the stone. Gold filled has a thick sheet of gold around a core of brass. Gold plating has only a thin layer of gold over a base metal. For gold filled, you should see a thick amount of gold on the stone. Gold plated will only leave a trace amount of gold on the stone. You will see much more of the base metal being transferred.
After you transfer the sample onto the stone, squeeze droplets of the acid onto the scratch sample. The acid is corrosive and anything that is not gold will simply disappear. For the component to be gold filled, the gold trace should still be there. If there is little or no trace (vast majority having disappeared), then it can be safely concluded that there was insufficient gold – either because of under-karating, or that it was plated and there was insufficient gold on the surface to be gold filled.
What is Gold Filled?
Gold Filled is an American metal manufacturing process and legal standard of quality . Gold filled is two sheets of solid karat gold (most popular being 14kt gold) bonded over (or for wire, rolled in tube) a core of brass. For a piece of jewelry to be legally stamped with the telltale ‘GF’ marking, its weight must be at least 1/20th gold. This explains the typical stamp you would expect to see on gold filled articles: “1/20 14K GF”, which means that 5 percent of the piece is 14 karat gold.
The surface layer of gold-filled jewelry is about 100 times thicker than any plating. Gold-filled pieces tend to last much longer and are considered ‘lifetime jewelry’. Gold plated jewellery is made using a thin layer of gold to surround base metals or sterling silver. The fine layer of gold is set using the method of chemical or electrochemical plating. It is the cheapest of the three forms of gold jewellery (solid karat gold, gold filled and gold plated). It is the quickest to tarnish.
Gold filled is not to be mistaken for gold plated, which is far less expensive than gold filled. A number of resellers in the industry have confused the market place by using those terms interchangeably. Many countries outside of North America use gold filled to mean gold plating. Problems occur when North Americans and Europeans purchase from suppliers listing their gold plated items as gold filled. Especially if they resell it as gold filled relying on their supplier’s product description. Gold plated brass or copper chains and connectors should NEVER be used on permanent jewelry. They simply do not last and designers and permanent jewelry artists will risk tarnishing their brand (pun intended).