Gold is considered one of the most valuable elements on Earth and has been used for various purposes by humans for a very long time. Throughout history, gold purity has been essential to its significance.
Measuring gold’s purity has been a widely accepted technique for centuries. Due to its durability, thickness, and shine, gold has been a popular choice as a store of assets long before it was used as currency.
For these reasons, it developed a measuring system, now used on other precious metals and gemstones.
Importance of testing gold purity
Testing gold purity is essential for several reasons:
- It helps you determine the value of your gold item, whether you are buying or selling it. To get the best deal for your gold, it is essential to know its exact weight and purity, which are the factors that determine its price. Therefore, it is crucial to be aware of the karat of your gold.
- Gold is commonly blended with other metals to achieve different colours and durability. However, some dishonest vendors may attempt to sell fake or low-quality gold as genuine gold. Testing gold purity can help you avoid being scammed or cheated. It enables you to ensure the quality and authenticity of your gold item.
- It helps you preserve the beauty and longevity of your gold item.
Different karats of gold have other properties and require additional care and maintenance. Knowing the purity of your gold can help you choose the right cleaning products and methods to keep it shiny and prevent tarnishing.
How to Identify the Purity of Gold and Testing
There are many ways to identify the purity of Gold. Some are simple home and visible-based tests, and some are laboratory tests.
Testing gold’s purity is simple and cost-effective. Pure gold lacks magnetic properties and does not react to it, but gold is often mixed with other metals to lower its purity.
If you want to check the purity of your gold, you can do so easily by using a simple magnet. Just bring it along and test your gold item to know its purity instantly.
Magnets can be easily found in the market. The item will likely be genuine gold if it does not attach to the magnet. A simple way to check the authenticity of gold items is to use a strong magnet at home.
Gold is a dense and sturdy metal. It can be used as a reliable and immediate method to determine whether a gold item is authentic. The weight and density of gold are strong indicators of its authenticity.
Drop it in a water bucket to check if your gold item is pure. If it sinks, it’s pure gold. Pure gold is dense and will sink in water. The item will float on the water’s surface if there are impurities.
This is another old-fashioned method that involves using a touchstone (a black stone with a finely-grained surface) to test whether the gold item leaves a mark on it. The mark can then be compared with marks made by known karats of gold to determine its purity. However, this method could be more reliable and accurate, as different factors such as pressure, angle, lighting, and colour can affect the mark’s appearance.
This is a mythological method that involves biting the gold item to test if it leaves an impression on your teeth or not. Pure gold is soft and pure gold is soft and malleable, so it should leave a dent in your teeth if you bite it hard enough.
However, this method is not recommended, as it can damage both the gold item and your teeth, and it needs to be more accurate, as other soft metals can also leave a dent. Moreover, biting gold can expose you to harmful bacteria or chemicals that may be present on the surface of the gold item.
The acid test is one the most accurate and dependable methods to determine gold’s purity. This test is authentic and can easily be carried out at home. If gold is pure, it won’t react with nitric acid but with other alloys such as zinc and copper.
When conducting the acid test, it’s essential to use caution due to the use of chemical substances. Be sure to perform the test in a well-ventilated room and wear gloves to protect yourself. Keep in mind that conducting the test at home may damage the beauty of your ornaments if they are impure.
If you want to check if your gold is real, you can use a gold testing kit with nitric acid and a black stone, similar to the one jewellers use. To test if your item is made of real gold, gently rub it on a rock and apply a small amount of nitric acid to the scratch. If there are any other metals present, the acid will dissolve them.
You can use your kitchen items to determine if your gold possessions are pure. Drop some vinegar on the gold article. If the gold is pure, the vinegar will not change the colour of the paper.
To ensure that your gold items are pure, you can use these straightforward methods to test their purity.
X-ray fluorescence Test
This modern method involves using an X-ray machine to scan the gold item and measure the radiation emitted by its atoms. The radiation reveals the composition and purity of the gold item without damaging it. This method is fast and non-destructive, but it may need help to detect thin platings or coatings on the surface of the gold item.
Inductively coupled plasma mass spectrometry (ICP-MS)
A modern method of analyzing the purity of gold involves using a plasma torch to vaporize a small sample of the item. The ions from the sample are then analyzed with a mass spectrometer to reveal the exact elements and isotopes present. Although accurate and sensitive, this method is destructive and requires expensive equipment and expertise.
Understanding Karat System
The purity of gold alloys is measured using the karat system. Essentially, it determines the amount of gold in the alloy compared to other metals. The plan divides the total weight of a gold item into 24 equal parts, and each part is called a karat (abbreviated as k). The greater the number of karats, the higher the purity of gold in the alloy.
For example, 24-karat gold is pure gold with no other mixed metals. It has 24 parts of gold out of 24 parts total.18-karat gold is 75% pure gold, with 6 parts of other metals like copper, silver, or zinc. 14-karat gold has 14 parts of gold and 10 parts of other metals, and so on.
The karat system originated from a medieval coin called a mark, which weighed 24 carats (a unit used to measure gemstones). The level of purity of the coin was determined by the amount of gold content expressed in carats. Pure gold was too soft to make coins, so other metals were added to make it harder.
The karat system indicates the quality and value of gold jewellery, colour, and durability. Pure gold is a delicate metal that can easily get scratched or dented. It is typically mixed with other metals to make it more durable and appropriate for daily use. Different metals also give different colours to gold, such as yellow, white or rose.
Gold jewellery typically comes in different karats, which include 9k, 10k, 12k, 14k, 18k, 22k, and 24k. Below is a table that compares these karats.:.
Millesimal fineness is another way of expressing the purity of gold alloys, using parts per thousand instead of parts per twenty-four. An alloy with a millesimal fineness of 750 indicates that out of 1000 parts, 750 parts are pure gold.
The colour of gold depends on the type and amount of other metals that are mixed with it. Yellow gold is the most natural colour, containing more pure gold than other metals. White gold is made by adding metals such as nickel, palladium or silver, which give it a silvery-white hue. Rose gold is made by adding copper, providing a pinkish-red tint.
Testing gold purity is essential to protect yourself from fraud and to get the most value out of your gold item. To ensure the purity of your gold item, purchasing it from a trustworthy seller who can provide a certificate of authenticity or a hallmark is recommended.
You can also take your gold item to a professional jeweller or appraiser who can test it using advanced equipment and methods. These are some ways to test gold purity, but they could be more foolproof and comprehensive. Find us here