How Do I Know It's Real Gold?

Have you ever pondered the value of grandmother’s old necklace? Contemplated if that ring from a few exes back is worth anything? Using a few simple tools from home, it is easy to determine if the trinkets that line your shelves and jewellery boxes are in fact real gold (greater than 10k).

There are a few ways in which to test. The first, and easiest, is to investigate the appearance of the piece in question. The following properties may help in finding out if the gold is real:

• Check for a stamp. Usually on the inside of a ring, or the side of a necklace clamp, there will be a number followed by a K. This displays the composition in “karats”. These stamps are usually correct, but can sometimes be off. This does not necessarily mean that if it isn’t stamped that it isn’t real, since not all gold pieces are stamped.

Because of the softness of pure gold, it is usually alloyed with base metals when creating jewellery. Alloys with lower percentages of gold contain more silver, copper, nickel, etc. The more karats in an item of jewellery, the greater the value.
 

Gold Composition Table

Karats	Compostion	Gold %
24k	24 Parts Gold	99.9%
22k	22 Parts Gold,  2 Parts Other*	91.6%
18k	18 Parts Gold, 6 Parts Other*	75%
14k	14 Parts Gold, 10 Parts Other*	58.3%
10k	10 Parts Gold, 14 Parts Other*	41.7%
	* Metal alloy, such as copper, nickel or silver

 

• Check for discoloration. Investigate high friction areas where gold may have worn off. This will prove that the piece is gold plated however, having no discoloration does not prove that it is real. 

• Investigate the color. The color of real, yellow gold is a warmer and buttery tone. Fake and fool’s gold has a brassier and lighter look. Be aware of shiny pieces.

Gold can be bright, but not shiny. Gold does not tarnish, corrode, or rust. Gold jewellery and coins in treasure chests and sunken ships are still bright and sparkling when discovered.

Once the appearance of the piece has been analyzed, and the authenticity has yet to be determined, one or more of the following experiments may be helpful: 

• Magnet Test. Bring a magnet near the piece of jewellery. Gold is not magnetic; therefore, if the piece of jewellery is attracted to the magnet, the composition of metals must be a higher percentage of other metals, rather than gold. Remember that at the same time, having no pull does not determine authenticity since it could be made from another non-magnetic material. 

• Streaks on a Plate. Find an unglazed, ceramic plate. Run the piece of jewellery against the plate and take note of the color streak that is left behind. If it is real, it will leave a golden streak. If the piece isn’t real, the streak will be black. 

• Softness Test. Poke the item with a pin in a spot that will be unnoticed. Gold is soft and malleable, so if real the pin will sink. If fake, the pin will break off, or be met with resistance.

Make sure to place the pin on the inside of a ring, or near the clasp of a bracelet, to eliminate any noticeable markings that may occur.

• Just Dunk It. Gold is very heavy. Fill a jug three quarters of the way with water. Drop the piece in question into the jug. If it sinks to the bottom, there is a higher chance of it being real. If it floats, it is likely not real. The only metal heavier than gold, is platinum

• Nitric Acid Test – Warning – make sure to take safety precautions if performing this experiment. Nitric acid is highly corrosive. While wearing rubber gloves and safety glasses, make a scratch with a file on an unnoticeable spot. Take a wooden, glass, or plastic stick to apply a small amount of acid on the filed spot of the jewellery. If there is no reaction, the gold is real. If the scratch turns a greenish color, it is gold plated. If it becomes milky, it is gold layered over silver. Make sure to wash everything well under running water after your experiment.

After checking the appearance and completing one or more of the experiments above, you should have a pretty good idea if the gold you are holding is real. Determining the value of your gold pieces is most accurately done by a jeweller, but to get a good idea of the range, and if it is real gold or fool’s gold, these tests will do just that.

So, next time you’re sifting through old costume jewellery, or counting out coins from your childhood collection, be sure to pull out your magnets and see what sticks.