XRF was valuable in that it did the following for this GNL ANS CC8R book:
1- It identified all the different off-metal Class 1 alloys such as brass, bronze, copper, german silver, etc. I believe we identified over a dozen Class 1 different metal alloys in our 1000+ specimen database.
2- It identified the various Ag levels in Class 2 counterfeits developed for the China market.
3- It identified the later Class 4 counterfeits of the modern era like the Fe/Ni plain edge 8R's from China using a cast die transfer process - predominantly.
4- It confirmed legitimate regal 8R's with ~90%Ag and good Pt/Au levels (i.e., 0.1-1.0% or more). A tool I used to indicate to me whether an 8R is a debased Class 2 or a regal specimen with GOOD silver, platinum and gold levels.
XRF is only composition. It really can't be used for determining origin with any high level of guarantee. We can make suggestions from the XRF data. Although outside the technical scope of this forum methods like Lead Isotopic Analysis, SEM/EDS on a coins internal microstructure and therefore its unique manufacturing fingerprint internal structure are showing promise in linking coins with a particular mint. A coin's make-up at the atomic level so to speak is the key to origin - not from an XRF compositional analysis ALONE. Currently papers are being published with this much higher level dual type methos (i.e., XRF & SEM/EDS, Lead Isotopic Analysis)to link coin with mint. Its mostly reserved for ancient coins at this point as ore mining sources, mint location and distribution centers are simpler for these coins than coins produced in the 18/19thC ... where MORE ore mixing is prevalent making origin determination more complex.
John Lorenzo
United States
1- It identified all the different off-metal Class 1 alloys such as brass, bronze, copper, german silver, etc. I believe we identified over a dozen Class 1 different metal alloys in our 1000+ specimen database.
2- It identified the various Ag levels in Class 2 counterfeits developed for the China market.
3- It identified the later Class 4 counterfeits of the modern era like the Fe/Ni plain edge 8R's from China using a cast die transfer process - predominantly.
4- It confirmed legitimate regal 8R's with ~90%Ag and good Pt/Au levels (i.e., 0.1-1.0% or more). A tool I used to indicate to me whether an 8R is a debased Class 2 or a regal specimen with GOOD silver, platinum and gold levels.
XRF is only composition. It really can't be used for determining origin with any high level of guarantee. We can make suggestions from the XRF data. Although outside the technical scope of this forum methods like Lead Isotopic Analysis, SEM/EDS on a coins internal microstructure and therefore its unique manufacturing fingerprint internal structure are showing promise in linking coins with a particular mint. A coin's make-up at the atomic level so to speak is the key to origin - not from an XRF compositional analysis ALONE. Currently papers are being published with this much higher level dual type methos (i.e., XRF & SEM/EDS, Lead Isotopic Analysis)to link coin with mint. Its mostly reserved for ancient coins at this point as ore mining sources, mint location and distribution centers are simpler for these coins than coins produced in the 18/19thC ... where MORE ore mixing is prevalent making origin determination more complex.
John Lorenzo
United States
Edited by colonialjohn
04/18/2013 11:50 am
04/18/2013 11:50 am






















