Frequently Asked Questions | Goldanalytix

For jewellery, there are many different alloys with a wide variety of metals. Since the magnetic scale measures very finely, even a small proportion of a ferro- or diamagnetic metal (e.g. nickel, platinum) can influence the result, making it no longer meaningful. Therefore, the magnetic balance is not suited for jewellery testing.

For jewellery, there are two main types of counterfeiting. One common form of jewellery counterfeiting is false hallmarks, i.e. sub-alloys in which a higher proportion of gold is stamped on than is actually present. The CaratScreenPen is the best device to measure the carat number of gold within seconds. Test acids or density scales can protect against this. The other form is the use of counterfeit materials, such as wolfram carbide jewellery with gold plating, or e.g. "Autobahngold", which often consists of gold-plated brass or stainless steel. Here, the GoldScreenPen can in some cases give important indications.

The best way to find out the composition of jewellery alloys is to use the CaratScreenPen from Goldanalytix. It measures the carat number of gold within seconds.

Another way to measure the composition of jewlery is by test acids or an XRF instrument. With the test acids it is possible to find out the carat content of jewellery, as well as some other components of the alloy. When analysing with an X-ray fluorescence device, it is even possible to determine the exact qualitative and quantitative composition of the alloy. For private customers, these devices are usually not profitable with prices of 20,000 € upwards.

For diamonds/gemstones, carat is a measure of weight. Here, one carat corresponds exactly to 0.2 grammes. In the precious metal trade, on the other hand, the gold content of bars and coins is indicated as the fineness or fine gold content, usually in the form of an embossing. The CaratScreenPen measures the carat number of gold within seconds. Pure gold bars are stamped 999.9, also known as "four nine fine".
Below you will find an overview of the carat specifications for gold:

8 Karat:
333
Gold 33.3 %

9 Karat:    
375
Gold 37.5 %

10 Karat:
417
Gold 41.7 %

14 Karat:
585
Gold 58.5 %

18 Karat:
750
Gold 75 %

20 Karat:
833
Gold 83.3 %

21 Karat:
875
Gold 87.5 %

22 Karat:
916,66
Gold 91.666 %

24 Karat:
999
Gold 99.9 %

No. The GoldScreenPen measures the conductivity (like the GoldScreenSensor) and is therefore ideal for counterfeit detection of coins, bars and silverware. Sub-alloys or the exact carat number cannot be measured with a carat number smaller than 21, because the conductance values ​​of these alloys only decrease very slightly with decreasing gold content.

The CaratScreenPen measures the carat number of gold objects, and therefore is the best method to detemine the carat number. The Goldanalytix test acids or the density scale are also methods to determine the carat number.

Bars or coins are usually made of pure gold or known alloys. For precious metal jewellery, however, there are many different compositions of the most diverse materials, which can be challenging task.

The CaratScreenPen is our solution for testing the carat number of objects containing gold. It measures the carat number of gold within seconds.

If you want to know in detail what to look for in jewellery testing, you can take a close look at our gold test page.