How Pure is Your Gold ?
Adulteration with Iridium, Ruthenium…………..???

Check & Show Karat by CKARAT XRF Technology.


Technical Note for Private Circulation
CKARAT XRF SPECTROMETER……CHECK IRIDIUM & RUTHENIUM IN GOLD ALLOYS

Adulteration of Gold with Iridium & Ruthenium, consequently its detection is a challenging task facing the Buyer, Seller & the Regulatory Agency.

By observing the Physical properties of Gold, Iridium, Silver & Ruthenium given in Table below one can understand why Iridium & Ruthenium escape the detection by the Fire Assay Technique used for the determination of Purity of Gold.

Element

Atomic Number

Melting Point

Density

Gold

79

1063

19.37

Iridium

77

2443

22,42

Silver

47

961

10,5

Ruthenium

44

2427

12,41

Due to their high melting points, the detection of Iridium & Ruthenium by Fire Assay Method is difficult as most of the Labs have furnace up to 1150 deg C coupled with the fact that when mixed with Gold, both Iridium & Ruthenium do not form an alloy but sit tight in the Yellow metal and are available in scattered form as fine particles. By visual inspection of the cornet after the fire assay process, the presence of Iridium & Ruthenium may be found as tiny black particles by skilled Lab Chemists.

CKARAT XRF Spectrometer can be used to check/detect the presence of Iridium and Ruthenium impurities in Gold Alloys. The Semi-conductor Detector has resolution apprx. four times that of the Gas-filled Proportional counter, and is thus able to resolve/separate the peaks of interest.

The Gold, Iridium, Silver & Ruthenium spectra using proportional counter detector and Silicon PIN Detector (SiPIN) are shown in the figures:-


 

 
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