Singapore Bullion Market Association

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The Importance of Hallmarking Gold

By Eric Law, Vice President and Deputy General Manager, Singapore Test Services

Published on September 10, 2021

With the uncertainty over Covid-19 lingering in global markets, gold prices are expected to continue climbing in 2021 as investors flock to the safe haven asset. Concerns over how this may impact the world’s economic rebound post Covid-19 mean that gold prices have the potential to push even higher in the near future.

The situation is further exacerbated by supply shortages from gold suppliers due to Covid-19 restrictions from source or supply countries.

All these factors in turn increase the risk of cheating or unethical practices of overstating the purity of gold by unscrupulous sellers or retailers.

The actual gold content of a piece of jewellery cannot be judged visually or by feel alone, as the type and amount of alloying metals added cannot be easily determined. Thus, it is not uncommon for the gold content in jewellery to be undercarated (overstated).

The addition of other cheaper platinum group metals elements to increase density is also becoming more prevalent. Without any assurance of purity, consumers may end up paying a lot more than the actual value of the gold item.


Hallmarking on gold is a guarantee of its purity, which safeguards consumers by ensuring that they receive the levels of purity stated on the item.

Not only does hallmarking enhance the credibility of gold jewellery and customer satisfaction, it offers consumers a higher resale or exchange value of gold articles as quality standardisation leads to price parity. More importantly, it offers legal protection to buyers of gold and gold articles.

From a trade perspective, hallmarking also benefits gold jewellery retailers immensely. By selling hallmarked gold, retailers can differentiate themselves from competitors selling unmarked jewellery. Providing such consumer assurance earns their trust and builds the foundation for sustainable business growth.

Unlike countries like the United Kingdom or Thailand which require mandatory hallmarking of gold jewellery and artefacts, hallmarking is voluntary in Singapore and is a service of the Singapore Assay Office (SAO), which has been in the business for over 40 years.

Wholly owned by Singapore Test Services, a subsidiary of ST Engineering, SAO is the only SAC Singlas accredited hallmarking laboratory in Singapore for hallmarking and is recognised by the London Bullion Market Association – an honour accorded only to establishments that have attained the highest level of assaying expertise.

SAO complies with the Singapore Standard 581:2020 specification for fineness and marking of articles of precious metals, and was part of the technical committee involved in drafting the standard.

SAO’s personnel use specialised instrumentation such as X-Ray Fluorescence Element Analysis (XRF) and high temperature furnaces to perform gold testing and fire assay techniques to determine gold purity.


Hallmarking of jewellery or articles is done manually or using laser marking machines depending on the shape and size of the item. The complete set of SAO hallmarks consists of the Jeweller’s mark, SAO mark and the Standard mark (Figure 1).

Figure 1: The Jeweller’s mark, SAO mark and the Standard mark

From left: Jeweller’s mark, SAO mark, Standard mark

The Jeweller’s mark represents the company or producer. The SAO mark represents quality and takes the form of a lion head. The Standard mark represents the purity of the element. For example: 999, 916, 22K, 750, 585, etc.

Figure 2: SAO Certified Member Decal

From left: Jeweller’s mark, SAO mark, Standard mark

Hallmarked articles are certified and assured of their gold purity and quality to help consumers safeguard their investments. The next time you purchase gold items, do look out for jewellery shops with the SAO lion head logo or the SAO decal (Figure 2).

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ERIC LAW is currently Vice President and Deputy General Manager for Singapore Test Services, a fully owned subsidiary of ST Engineering. Eric leads the various operations within Singapore Test Services such SAO Office since 2019. He previously held various management position at ST Engineering.