How to know if a jewel is gold

Jewelry gifts are among the most elegant and perhaps the most valuable that can be given to someone very close. This type of jewelry is usually of high quality, as it is made from a noble metal, such as silver, platinum, and, of course, gold, the precious metal par excellence, since it is a material with great value due to its characteristics, but also because of its scarcity.  Thus, it is likely that doubts arise when you want either to give a gold jewel to someone or simply share it to wear it, whether it is a pendant, earrings, a ring, or a bracelet, etc. Among these doubts, you may wonder how you can know if what you have bought or are going to buy is really pure gold. We have all heard on some occasions about someone who went to the jewelry store fully convinced that the family heirloom they want to sell is pure gold, only to discover, after the jeweler's examination, that it is not a first-class jewel but another lower-quality material covered with a thin sheet of this noble golden material.  To avoid this kind of unpleasant surprises, in this article we will talk about some methods that exist to check if a piece is pure gold or simply a silver or bronze jewel plated in gold. Therefore, we will explain what you should look for to verify the quality of the material and know that the jewel you are buying is worth exactly the price you are paying for it. There are several ways to check it.

Visually examine the piece

If you have a piece of jewelry and wonder how to know if it is gold, you should look closely at all the smallest details of the jewel itself to find a mark or official stamp indicating the proportion of pure gold it contains. You can find them in different carats, such as 10k, 14k, 18k, and 24k. Besides this, it is possible to trace the manufacturer's mark in another small stamp, especially if the jewelry pieces are from after 1950, since before that, no stamp was included to identify them.  You should also know that if the piece is made of a lower-quality material plated in gold, the jewel must contain another type of stamp, mark, or nomenclature to identify and differentiate them from those of better quality. For example, the GP stamp indicates that the piece is gold plated, while GF means it is plaqué - a gold layer adhered to another lower-quality material -, and GEP means the piece is electroplated, that is, covered with gold through an electrochemical process.  If you do not find any stamp, it is likely that it is either a good quality gold piece from before 1950 or a current piece that does not contain enough of this valuable golden metal to be considered a jewel with a high gold proportion. Therefore, you should look for any area on its surface that has a different color, contains rust, or appears discolored. This is a good indicator to know the quality of the material since gold is completely stainless and does not discolor over time.  If you find any discolored area, with rust or a color different from the rest of the golden jewel, it is likely that the piece contains a lower-quality material inside and has been gold-plated. However, this visual examination should be complemented with a more reliable one to confirm that the piece is not made of pure material. 

Check the hardness of the material

If you ask how to know if a jewel is gold, you can check its hardness. Strange as it may seem, gold is a metal not characterized by its hardness but is easily malleable and can be scratched easily. It is one of the methods most used since ancient times to check if a piece is pure gold or not, since if, when scratched, another color appears, it is clear that it is a jewel made of a lower-quality material but covered with a thin layer of gold. However, if the golden color remains after scratching several times, it is very likely to be pure gold.  The most used method from ancient times until a couple of centuries ago was the bite test, because human teeth are harder than gold, so a bite can leave marks on its surface, penetrating several layers of the material. However, this method was discontinued because it damages the jewel and some materials look very similar to gold at first glance and can pass this test. 

Perform the gold density test

If you want a more reliable test, there is the gold density test, as it serves to check the purity of this noble material contained in a jewelry piece using a densimeter. If the piece shows a density of around 19.32 gr/cm³, it means we are dealing with a pure gold piece, while if this value is different, it is likely that the piece is plated, electroplated, or gold-bathed and contains lower-quality materials inside. Although it should also be said that it may be an alloy of gold with another material. 

You can use the nitric acid method

It is likely the method that provides the best results and, therefore, is the most reliable of all if you want to find out how to know if a jewel is gold. But when performing this test, you must be careful because the material used, nitric acid, is potentially dangerous, so you must handle it carefully to avoid contact with skin or eyes, as it can cause very severe burns upon contact.  This method is based on placing the jewelry piece on a stainless steel plate and then pouring a few drops of nitric acid on it and observing if there is any chemical reaction. If the piece does not react in any way or change color, it means it is pure gold. On the other hand, if it reacts, it is because it is simply a gold plating over another material. 

Use a laser tester

Compared to the nitric acid method, the laser tester is a safe and one of the most reliable methods available, as it allows you to know exactly the degree of purity of the material, obtaining results instantly. It is perhaps the method most used by specialists to know the purity of a gold piece because it is very reliable and much safer for health, minimizing the risk of accidents to the maximum.