The value and quality of gold are directly affected by its purity. Normally, gold purity is measured in karats or as a percentage, indicating how much of the metal is pure gold and and how much consists of other alloys. However, different gold carats affect value, durability and skin compatibility in different ways, making price just one of several factors to consider when purchasing gold. While gold may shine, not all of it is pure. Most jewellery includes other metals, rendering purity checks a vital step for buyers and sellers alike.
If you are considering a gold purchase, seeking a loan or about to invest in it, then having a clear understanding of gold and testing methods can save you from financial losses. With the rise of the digital revolution, advanced techniques now make it easier to know how to check gold purity, putting an end to the fraudulent activities that scam gold buyers.
In this blog we will explore various techniques to check gold purity and guide you towards taking informed decisions, ensuring you do not fall into any of the potential traps in gold transactions.
Purity is what defines gold. But how do we know which of them are pure and which of them are impure? Here are three key features you must consider when learning how to check gold purity.
Carat is a measure of gold purity in an alloy. The higher the carat, the purer the gold. Among various forms, the 24-karat gold of 99.9% gold is the purest followed by 22K, 18K and 14K gold in decreasing purity.
24K: Pure gold, or 99.9% pure.
22K: 91.6% pure, often seen in jewellery.
18K: 75% pure, popular for durability.
14K: 58.5% pure, common in affordable jewellery.
10K: 41.7% pure, used for everyday jewellery.
Fineness measures gold purity on a scale of 1,000. You may have heard the term ‘916 gold’ at some point in your life. It indicates the purity of 22K gold, while 999 refers to 24K gold. This measurement is commonly used to represent the purity of gold in international markets.
The adornments that we wear is not 100% gold, it is a mix of alloys such as copper, silver or nickel. Besides, pure gold (24K) is very soft, so alloys are added to make it suitable for jewellery and everyday use. Also, the gold purity depends on the gold ratio in the composition. For example, 18K rose gold is 75% gold, mixed with the right proportion of copper and silver.

Also Read : How to Check Hallmark on Gold Jewellery
In India, there are certain criteria that need to be met when you buy jewellery. The BIS hallmark is a certification issued by the Bureau of Indian Standards (BIS) to verify the purity of gold and silver jewellery. Reputable jewellery brands across the country typically stock only BIS-hallmarked jewellery to ensure purity and authenticity. It features three distinct marks namely BIS logo, Purity/Fineness grade and Hallmark Unique Identification(HUID). If you identify all three hallmarks on the jewellery you purchase, then you can confidently buy it.
The acid test in jewellery is a traditional method used to check the purity of gold. The process involves applying drops of specific acids such as nitric acid on to the gold and observing the changes that occur upon adding them. If there is no reaction, the gold is of the claimed karat; but if the color changes or a reaction occurs, it indicates that the gold is less pure or mixed with other metals
The magnetic test is the simplest method to identify whether a gold is real or fake. Gold is a non-metallic element. Therefore, when a magnet is placed near it, gold does not respond to a magnet. And if it is attracted to a magnet, it is a clear indication that the jewellery contains other metals, particularly magnetic ones, mixed with gold.
Because gold has a high density, its purity can be ascertained by measuring its weight and volume. After weighing the gold, measure its displacement by immersing it in water. To find the density, divide the weight by the volume. Pure gold is suggested by a density of around 19.3 grams per cubic centimeter.
This test uses X-Rays to measure the proportion of metals in the gold. It is a common method followed by professionals in the jewellery business.
Electronic testers use electronic conductivity to determine the gold purity of the jewellery. It provides a fast, reliable and accurate assessment of an item’s karat value while also verifying whether it is made of gold or just a gold-plated imitation.
Ultrasonic testing employs sound waves to assess the density and structure of gold, helping jewelers identify counterfeit or hollow pieces.
This is a traditional method to identify the gold purity which involves melting the gold sample and separating it from impurities to precisely measure its purity.
There are several hacks to examine how to check gold purity. Start by checking for a hallmark or BIS stamp which provides assurance of authenticity and opt for other testing such as acid test or density check to further validate the gold purity check. However, a quick and easy approach to test gold at home is to purchase a tiny gold purity tester which can confirm its authenticity. Also, having an understanding of the carat values such as the 22 carat gold purity or 24 carat gold purity percentage, can provide insights about the purity level of the jewellery and be helpful in making informed decisions. For the most reliable results and to avoid any risk of damaging your jewellery, it is wise to seek professional help and ensure damage-free purity testing results.
Determining the gold purity of the jewellery is as important as preserving the quality of your collection. Therefore, understanding how to verify gold purity is a key aspect even if you are purchasing, selling or ensuring your jewellery is genuine. Applying any of the above mentioned techniques can prove beneficial in the long run and help you stay mindful of the potential challenges. At Jos Alukkas, we surpass merely offering exceptional designs by ensuring every product we offer carries all the necessary certifications, is tested, and verified before being dispatched to our customers. Our certified jewellery collection reflects our commitment to excellence, authenticity and trust.