What is a Silver Assay?

Often in the physical bullion industry, you may come across precious metal bullion bars which often come packaged with assay verifications further ensuring the product’s guarantee. Here we explain what silver assaying is with videos showing how we typically assay silver still today.

A precious metal assay is designed to test the composition of valuable metal ore.

Most bullion products we sell are respectively silver bullion and gold bullion, and a gold assay or silver assay is a way to make sure that all the bullion coins or bullion bars produced by bullion mints meet the correct purity standards and content claimed.

For example, if the US Mint guarantees that a gold coin has 99.99% purity or made with .9999 fine gold, a gold assay is necessary to make sure that all the gold minted in that coin indeed meets those guaranteed standards.

The practice of assaying gold and silver goes back thousands of years and the method is still in use today.

Although most countries, including the United States, no longer use circulated gold coins or circulated silver coins for day-to-day commerce. The precious metal assay process still used by many government bullion mints who produce investment grade bullion products.

Content purity is still essential in the creation and guarantee of silver coins and silver bullion bars for example. 

There are many methods to assay gold, silver, and other physical precious metals.

Here we will focus on the most typically accurate and time tested method for assaying precious metals, the fire assay.


The precious metal 'Fire Assay' process has been proven best for thousands of years in measuring the certain concentration levels of high-value materials for gold and silver mining, recycling, and refining.

Although fire assays are somewhat time-consuming, invasive, and work-intensive when compared to instrumental XRF, ultrasonic sound, or specific gravity analysis. Fire assays done correctly are often more reliable and accurate in most cases.

Fire assays generally involve three significant steps:

1) Fire Assay Preparation - grinding or milling samples into a fine powder. Reactants are then often added.

2) Fire Assay Collection - usage of ceramic crucibles which will hold the assay sample during the heating and melting of the alloy. Lead fusion is the typical method used in this step.

3) Fire Assay Separation - cup-elation often occurs in a cupel, a porous bone-ash or calcium phosphate container.

The following embedded short video clip will take you through each step of typical the Silver Assaying process using fire more thoroughly.



US Mint Silver Assays & Gold Assays

The United States Mint makes many of the world’s most popular bullion products made with silver, gold, platinum, and palladium.

Give that the US government guarantees the troy ounce weight and explicitly stamped fineness of all the 22k gold coins, 24k gold coins, and pure .999 silver coins. It is no surprise they take the charge of Silver Assaying very seriously.

The following video footage was shot in the US Mint's West Point location. The US Mint's head chemist explains more about the silver assaying process they use to ensure what they produce and sell is the bonafide article.



So long as precious metals get mined, refined, and recycled. This Silver Assaying process using fire and high-temperature melts and measurements will likely remain the most accurate and utilized method to assay silver and gold.

Learn more about the 21st Century bullion buying best practices as well as fundamental factors to invest in gold and how to safely invest in silver using prudent long term bullion allocations ongoing.

Thanks for visiting us here at SD Bullion.


← Previous Next →
We can't find posts matching the selection.
James Anderson
James Anderson
Senior Market Analyst & Content

A bullion buyer years before the 2008 Global Financial Crisis, James Anderson is a grounded precious metals researcher, content creator, and physical investment grade bullion professional. He has authored several Gold & Silver Guides and has been featured on the History Channel, Zero Hedge, Gold-Eagle, Silver Seek, Value Walk and many more. You can pick up Jame's most recent, comprehensive 200+ Page book here at SD Bullion.

Given that repressed commodity values are now near 100-year low level valuations versus large US stocks, James remains convinced investors and savers should buy and maintain a prudent physical bullion position now, before more unfunded promises debase away in the coming decades...