Analysis of Gold Jewellery Using the Niton XL2 from Thermo Scientific

[ThermoPortables]

See answers A1 and A2 ...

[ThermoPortables]

A2. ...Most circulated coins will have clear specifications of all these things as well as elemental makeup, so if one of these tests don’t match then it can be a suspected as counterfeit. In the case of bars, we always recommend drilling into the core of the bar and analyze the drillings. This doesn’t affect the value since all the material can be retained. If tungsten or silver is present, it will immediately become very apparent in the drillings.

[ThermoPortables]

A1. There are a number of ways to determine authenticity of coins,bars,other precious metals. Choosing correct method highly dependent on individual needs and what is tested. The counterfeits are becoming more sophisticated, so regardless of test the user must always exercise some caution. If you are coin dealer, careful inspection of the coin for dimensions, weight, stamp markings and XRF analysis will give you what you need to make a correct determination of coin’s authenticity....

[AuroTest]

blanks, which are matching perfectly the density of pure gold and are still much cheaper even when alloyed with with 3 % rhenium. Have a look to ATS 1000 ultrasonic/density precious metals testing sets in the Internet.

[AuroTest]

Yes, X-Ray fluorescence analysis can only check for the element chemistry of the upper 5 to 8 micron depth in gold and up to 50 micron in silver (with max. 50 kV voltage) . What is beyond that thin layer is impossible to see with such instruments. But the combined ultrasonic and density (specific gravity) testing is better suited for gold bars and coins, since larger bars (100 g and more) and coins can contain tungsten or tungsten alloys (e.g. W3Re) in the form of rods, plates and round

[polygamous1]

it is of course good to have a device like this But how about the cost? am sure most of us can't efford to buy one instruments like that do Not come cheap this am sure of also r they as good as X ray machines for this purpose? cause i heard of tungsten plated gold sold to china as tungstest has very similar specific gravity as gold?

[goldman310]

Would this work if the item had diamonds in it? Also would this work if the item was plated? Thank You..

[goldman310]

Would this work if the item had diamonds in it?

[azomdotcom]

@goldman310 Thermo Scientific Niton XRF Analyzers cannot detect carbon, which is what diamonds are made of. Therefore diamonds will not affect the analysis of the precious metal surrounding them. If the item is plated, most likely the analysis will penetrate the plating layer and show the substrate beneath (such as copper and silver) and display a very low gold content reading from the plating layer. 

[azomdotcom]

@goldman310 Thermo Scientific Niton XRF Analyzers cannot detect carbon, which is what diamonds are made of. Therefore diamonds will not affect the analysis of the precious metal surround them. If the stones are cubic zirconia (CZ), the analyzer has the ability to pick up the Zr signal, thus indicating that they are not real diamonds. However as a general rule, you want to place the material to be analyzed in front of the analyzer’s window and try to keep any stones out of the analysis path.

[goldhunting]

Guys, sorry, even after posting your link, only 9 people looked.

Anyway, someone said these testers of yours only tests the surface and would be of no use testing like gold bars.

But then, the idea originally was like fake gold coins and such. So, just how deep do these test?

[azomdotcom]

@goldhunting Yes, XRF technology is surface analysis technique. However, there are many refineries that use Thermo Scientific Niton XRF analyzers for assaying of gold bars. If the bars are homogenous, then a surface analysis is a good indication of the chemistry of the entire bar. Taking several readings on different areas of the surface and taking the average of the readings is good practice. Niton XRF analyzers can do this averaging on-the-fly and immediately display the results to the user.

[goldhunting]

Hi guys, thanks for a very informative video. I gave a link to you on the Kitco board. They were talking about undetectable fake gold.

That's sort of an interesting thought, if someone could make a fake gold in which even your xray analysers couldn't tell the difference?

[azomdotcom]

@goldhunting It is very difficult to “fool” Thermo Scientific Niton XRF analyzers since they operate on fundamental physical principals. These physics cannot be altered by people trying to pass off other materials as gold or other precious metals. There are many instances where people have been able to fool acid tests or other technologies by using stainless steel or other types of “fools gold.” These XRF analyzers easily detect these materials and will tell the user what the items are made of.

[vincecate]

@azomdotcom If I use it on some gold plated jewelry will it say it is gold or not gold? I am interested in using it to buy gold for a "cash for gold' type business where there is a lot of gold plated stuff.

[ThermoPortables]

@vincecate “Although x-ray fluorescence (XRF) technology is generally considered a surface analysis, there are ways to interpret the XRF results to assist in determining if an item is plated. Analysis results will show the gold content of the plated surface, and in the case of most plated items a strong signal will also come from the substrate underneath the plating. These results often show a relatively low gold concentration in comparison to the substrate material. (continued next comment...)

[ThermoPortables]

@vincecate (continued from previous comment) ... In the case of heavily plated items, there are other methods in which XRF can be used to help identify these items. Your local Thermo Scientific Niton Analyzer representative can discuss these methods in detail with you.”