How to Test the Purity of Your Gold/Silver
A follower recently asked me about the Sigma Metalytics device (officially called the Precious Metal Verifier, or PMV), which is commonly found at bullion shops. You'll often see staff using it to verify the purity of gold or silver items they're selling to customers or buying from them.
I own a PMV myself (Photo 1), and for anyone considering purchasing one for personal or home use, I highly recommend it. I bought mine on eBay in April 2016, and even though it's now 10 years old, it still works perfectly (I use it occasionally—perhaps on a few pieces once a year—and it was functioning fine the last time I tested it last year). The total cost, including international shipping and import charges from the US seller, was US$779.77. I just checked the Sigma Metalytics website, and they're currently listing the same model for SGD$1,302 (see Photo 2), though the company notes that all units are sold out.
I can't guarantee the exact contents will be identical if you purchase one today, but here's what I received 10 years ago. It came in a carrying case labelled "Basic Set" on the handle (Photo 3). In addition to the main unit (front shown in Photo 1, back in Photo 4), the kit included several accessories (Photo 5): a USB cable for charging, a calibration medal, and two sensor wands (one large and one small; Photo 6). You don't actually need the wands for most tests—you can simply place your bar or coin directly on the device's main sensor (Photo 7) and get a reading.
The kit also included a 12-page user guide written entirely in English (Photo 8). On page 1 (Photo 9), there's a clear diagram labelling the various parts of the device.
The PMV is relatively straightforward to use. If it's your first time powering it on after a long period, charge it for an hour or two first. Once turned on, select the type of metal you're testing (e.g., pure gold, 91.7% gold, 99.9% silver, platinum, palladium, etc.). Place the item on the main sensor (as shown in Photo 7), then check the screen (Photo 10): if the black cursor box falls within the brackets, the item is within the expected purity range; if it's outside, it may not be genuine.
I really like the PMV and highly recommend it. It's proven very durable for me—despite being 10 years old and used only occasionally, the battery still holds a charge, which speaks to its build quality. Part of that durability likely comes from its simple design: the display isn't a modern LCD but a reliable analogue-style screen.
Why did I buy one? When I first started investing in gold and silver over a decade ago, I wasn't aware of bullion shops and was purchasing silver coins from individual sellers on eBay Singapore. Once I discovered bullion dealers, I stopped buying from random online sellers. As mentioned, almost every bullion shop counter is equipped with a PMV—if you're ever unsure about an item's purity when buying from them, just ask to test it on the spot using their device.
That said, if you prefer hunting for better prices on platforms like Carousell (or similar peer-to-peer marketplaces) and meeting sellers in person, owning your own PMV is a great idea. You can bring it along to verify the bullion's authenticity during the meetup.
If you’re considering purchasing your own device to test precious metals, here are some practical tips based on my personal experience with the Sigma Metalytics PMV. Firstly, always ensure the device is fully charged before testing. I recommend charging it for an hour or two if it hasn’t been used in a while. Also, familiarize yourself with the user guide or seek online tutorials to understand how to interpret the results properly — the device shows a cursor within brackets to indicate purity within an acceptable range, but if it falls outside, further verification may be needed. When testing, place your gold or silver item directly on the main sensor for the most accurate reading. Avoid moving the item during measurement and try to keep the temperature of the item stable as extreme temperatures can affect the reading. While the PMV is very reliable, for high-value or heavily embossed coins and bars, consider cross-verifying purity through multiple methods like acid testing or professional assay services for added assurance. Finally, owning a personal verifier becomes especially useful if you buy precious metals from peer-to-peer platforms or informal sellers. Taking the PMV to in-person meetups helps you confidently verify authenticity on the spot, preventing potential losses from counterfeit or impure bullion. Overall, combining the Sigma Metalytics Precious Metal Verifier with careful purchasing practices can significantly enhance your confidence and security when investing in gold and silver.
