What is Gold Purity? 

Gold has always been known as a precious metal that is used in jewellery, and gold jewellery comes in many different fineness, or also known as purity.  

Fineness expresses the purity of gold in parts per 1000. In other words, if a metal was split into 1000 parts, how many of the parts are pure gold. For example, common gold fineness numbers 750, 916, and 999 indicate that in 1000 parts of that golden object there are 750, 916, and 999 parts of pure gold accordingly.   

Gold purity is commonly measured in karats, for example 18K, 22K, and 24K.  

The karat, K in short, is used to denote the purity of gold in the final product - out of 24K, which is pure gold. This is not to be confused with the carat (c) unit of mass that is used to weigh diamonds. 

For example, 18K gold means that there are 18 out of 24 karats, which also means that there are 75% gold, therefore also known as 750. The general rule is that the value of gold is proportionate to its purity - the purer the gold, the higher the value. 

How to check the purity of gold? 

Price 

When buying gold, do check the gold price on the market and from various stores. It is normal for jewellery’s gold rate to be slightly higher than online market rate for gold (rates for “paper gold” where you do not get to physically take anything). For easier reference, you may also imagine how rates at money changers are typically different from market exchange rates.  

If the final purchase price of a jewellery is so cheap that it seems too good to be true, there might be a chance that it is not real gold, or that the jewellery is gold-plated only. 

Company Brand 

It is always recommended to buy gold from official and reputable companies that has been around for a while. With the advancement of technology now, it is also extremely easy to look for reviews of brands online, be it from Google reviews itself or on the various marketplaces such as Shopee and Lazada. It is likely that brands selling fake or plated gold without telling customers will be exposed by over time. 

Official Evaluation and Hallmarks 

If you really want to be sure about the authenticity and purity of the gold, the best way is to look for an official assay office (responsible for testing and certifying precious metals purity in the country or region) hallmark. In Singapore, the only assurance of gold authenticity in Singapore is through Singapore Assay Office (SAO).  

Learn more about SAO here.  

References:

https://www.arthesdam.com.sg/blogs/news/the-ultimate-guide-to-buying-916-gold-22k-jewellery

https://www.arthesdam.com.sg/blogs/news/yellow-gold-compared-24k-22k-18k-and-more

https://www.arthesdam.com.sg/blogs/news/white-gold-vs-yellow-gold

https://www.gold.org/about-gold/about-gold-jewellery

https://www.paysera.com/v2/en/blog/gold-fineness-check