Frequently Asked Questions | Goldanalytix

Here you find answers to the most frequently asked questions on all topics related to precious metal testing. The questions and answers are neatly arranged according to key topics - so you can find what you are looking for very quickly.

Non-destructive precious metal test

How do I test gold for authenticity?

1. Compare the dimensions with the manufacturer's nominal dimensions.

2. Check that the weight is correct.

3. Measure the conductivity using the eddy current measurement.

For the last step, we recommend the GoldScreenBox for investment metals up to approx. 50/100 grams (depending on the dimensions). You can find more information (also on different sizes and shapes of precious metals) on our gold test page.

How are the GoldScreenBox and GoldScreenPen working?

The GoldScreenBox and the GoldScreenPen measure the conductivity of your precious metal object using eddy current testing. The coil of the respective device induces a magnetic field that creates eddy currents in the object. This allows the conductivity to be determined, which the tester outputs in megasiemens per metre.

Each precious metal has a specific conductivity, therefore contamination would be immediately noticeable in a measurement. If a precious metal is underalloyed or has a core of foreign metal, our devices show you this with a target/actual value comparison. The GoldScreenBox additionally gives you the result in the form of a coloured illustration of green, yellow and red.

Can test devices confirm the authenticity of precious metals non-destructively?

All Goldanalytix testers measure physical properties of the item being tested. It is easy for counterfeiters to imitate a single physical property, such as the density of gold with a wolfram core. However, the substitute materials or alloys are so unique in their characteristics that the imitation of another physical parameter, such as electrical conductivity, is unsuccessful. In order to obtain certainty, we therefore always recommend a combination of methods for checking authenticity. Starting with calipers and precision scales (coarse density estimation) to density scales (for imperfectly cylindrical or cuboid objects) to conductivity measurement or magnetic testing to ultrasonic measurement. All measuring methods have their justification depending on the application purpose and can effectively protect you against counterfeiting.

HERE you will find information on which device for non-destructive precious metal testing is right for you.

Does the conductance of Ag 999 and Ag 9999 differ?

In fact, the nominal value of 9999 silver with approx. 62 MS/m is slightly higher than that of 999 silver with 60.5 MS/m. Of course, when measured in practice, the values deviate slightly from the nominal value due to temperature, minting and packaging.
Coins with the fineness 9999 can therefore be in the higher green and sometimes also in the yellow zone.
Silver coins with "only" 999 of 1000 parts of silver are now and then in the lower green or even in the adjacent yellow zone (displayed on the GoldScreenBox).

Is the sound test a good counterfeit detection method?

The sound test is only suitable to a limited extent for a reliable authenticity check of precious metals. With experience you can detect forgeries, but with some alloys or certain manufacturing processes (e.g. sintered forgeries) the sound can be imitated very well. Therefore, this test is not recommended. 

We suggest other and safer methods and devices.

Is X-ray fluorescence the best test method?

An X-ray fluorescence spectrometer is very expensive. The price of such a device starts at 10,000 to 20,000 euros.

It is also only conditionally suitable for counterfeit detection: This method can only penetrate about 5 µm into the material. Underalloyed surfaces can be exposed, but common galvanised counterfeits with a gold-plated surface cannot!

The testing devices from Goldanalytix with their significantly higher penetration depths reliably protect you from forgeries - for a noticeably lower price.

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