Presentation Outline 1. Testing jewelry materials 2. What is XRF? 3. Who uses it? 4. Jewelry and other precious metals applications 5. Examples of XRF results 6. How accurate/precise are the results? 7. Instrumentation options For more information, visit: https://www.olympus-ims.com/en/vanta-for-precious-metals-analysis/

1. Olympus Analytical Instruments | Jennifer Caban
Portland, OR, Oct. 2017
Identifying Precious Metal Alloys
on Your Bench and in Your Case
Portland Jewelry Symposium 2017

2. Page 2
Olympus is a Global Organization
Founded in
Tokyo, Japan
1919
Expanded
to Europe
1964
Followed by
the Americas
1968
Followed by
Asia Pacific
2011
Opened under the name
Takachiho Seisakusho

3. Page 3
Consumer
Products Group
Scientific Solutions
Group
Medical
Group
PRECISION IMAGING TECHNOLOGY

4. Speaker Credentials
¡ 8 years working with X-ray fluorescence and X-ray diffraction
technologies in both technical and sales support roles
¡ Currently serves as a Sales Engineer (technical specialist) supporting
the Olympus Americas sales network
¡ Works with many industries, including scrap metal recycling, large-
scale and small-scale mining, government regulations, consumer
product manufacturing, environmental remediation, infrastructure
inspection, oil & gas production, academic geology, anthropology and
earth science, and precious metals refining and trading
¡ In charge of business development efforts for mining, geochemistry,
and earth science applications for Olympus Americas
¡ Bachelors of Arts in Environmental Economics from Bates College
Jennifer Caban

5. 1. Testing jewelry materials
2. What is XRF?
3. Who uses it?
4. Jewelry and other precious metals applications
5. Examples of XRF results
6. How accurate/precise are the results?
7. Instrumentation options
Agenda

6. ¡ Sight: naked eye or jeweler’s loupe; must be an expert
¡ Feel or bite/scratch test
¡ Weight/density
¡ Magnet test
¡ Markings (925, 14k, etc.)
¡ Nitric acid
¡ Laboratory assay: fire assay, ICP, atomic absorption, titration
¡ XRF! (X-ray fluorescence spectroscopy)
How are Jewelry Materials Verified?

7. XRF = X-Ray Fluorescence
¡ Note: Olympus also does XRD
− XRD = X-Ray Diffraction
¡ Shorter wavelengths = higher energy

8. ¡ The study of the interaction between matter and
electromagnetic radiation
Spectroscopy

9. What is X-Ray Fluorescence Spectroscopy?

10. XRF at the Atomic Level
Nucleus
− Protons
− Neutron
Electrons
− Orbit around the
nucleus
Orbit
− Aka “energy
shell”
X-rays impact
electrons

11. X-Ray Fluorescence Physics

12. Lost electron

13. Fluorescent
Energy
Element-specific
signature energy
emitted

14. XRF is a Statistical Method
Ni
Fe
Cr
Mo
Test Sample
Up to 300,000
photons/second

15. ChemistryCalculationMeasurementRe-EmissionExcitationX-Ray Emission
XRF Testing Process
Mn
F
eNi
Cr

16. ¡ After excitation, the atoms return to their original state
XRF is Completely Nondestructive

17. Unlike Other Forms of Jewelry Testing

18. Human
Origins
50.05%
Natural
Origins
49.95%
Sources of Radiation Exposure (in the US)
¡ 620 mRem, typical annual exposure
Source: https://www.nrc.gov/about-nrc/radiation/around-us/sources.html

19. Medical
Procedures
35.96%
Nuclear
Medicine
11.99%
Consumer
Products
2.00%
Industrial and Occupational
0.10%
Radon and
Thoron
36.96%
Cosmic
(space)
5.00%
Terrestrial
(soil)
3.00%
Internal
5.00%
Sources of Radiation Exposure (in the US) 620 mRem, typical annual exposure
Source: https://www.nrc.gov/about-nrc/radiation/around-us/sources.html

20. Active Monitoring and Typical Exposures
¡ Olympus employees who use XRF are actively monitored for radiation
exposure
¡ All Olympus employees are <20 mREM per year
Activity Exposure
Smoking 280 mREM per year
Mammogram 70 mREM
Dental X-ray 10 mREM per X-ray
Chest X-ray 8 mREM per X-ray
Drinking water 5 mREM per year
Cross country flight 5 mREM per trip
Source: https://www.nrc.gov/about-nrc/radiation/around-us/doses-daily-lives.html
Source: https://www.nrc.gov/about-nrc/radiation/rad-health-effects.html

21. Occupational Limits (in US)
Maximum Permissible Limits from
– National Council on Radiation Protection (USA)
– International Commission on Radiological Protection
– Nuclear Regulatory Commission (USA)
– State of Massachusetts (Local Example)
– Health & Human Resources -Dept of Public Health
Portion of Exposure Limit (mREM/yr)
Hands & Feet 50,000
Eyes (lens) 15,000
Skin 50,000
Thyroid 50,000
Whole Body 5,000
Source: https://www.nrc.gov/about-nrc/radiation/health-effects/info.html

24. Applications

25. Built-In GPS Enables Contamination Mapping in Real Time

26. ¡ Gold (Au), silver (Ag), and platinum group metals (PGMs)
¡ Non-precious alloying metals
¡ Contaminants
¡ Can detect Au plating
¡ Can differentiate and detect some fake gemstones—ex.) diamond and cubic zirconia,
turquoise, and leaded glass
Jewelry Applications

27. ¡ Gold and other precious metals in electronic scrap
¡ Verify the chemistry of incoming materials
¡ QA/QC of manufactured components
¡ Coating thickness
¡ Car catalyst analysis
Other Precious Metals Applications

28. ¡ XRF is a surface analysis technique
¡ In metals, the penetration is approximately 10–30 microns
¡ Human hair thickness is 17–180 microns
¡ Olympus also makes ultrasonic testing (UT) instruments
¡ Ultrasonic waves traveling through any medium will continue propagating in the same direction until
they strike a boundary with a different material
¡ Reflections coming from inside a gold bar, rather than the opposite surface, change the pattern and
indicate either an insert of another metal or an internal void
Fake Gold Bars

29. Examples
Photos courtesy Jennifer Caban

30. Gold Leaves
Low Au indicates that the leaves are gold plated. This is a copper alloy with thin gold plating.
Photos courtesy Jennifer Caban

31. Sterling Silver Earrings
Cadmium is a highly toxic metal. It should not be in jewelry!
The earring is labeled “925,” which means it should be
92.5% Ag. In fact, it is only 82.7% Ag.
Photos courtesy Jennifer Caban

32. The post (the part that
goes in your ear) has
an even higher
cadmium
concentration. This is
not good.
The European Union’s RoHS directive limits the
concentration of dangerous substances in electronics.
According to this standard, cadmium should be below
0.01% in electronics. The earring posts have > 20%
cadmium!

33. ¡ The sample is the biggest factor
− Is it homogeneous?
− Does it have surface contamination?
¡ Technology is also a factor
− Detector type and resolution
− Si PiN or SDD
− Electronics’ stability
¡ Analysis time
− Generally, longer is better
− Maximum of 60 seconds for alloys
How Reliable are the Results?

34. XRF Versus Other Techniques
Techniques Options Typical Accuracy
Fire assay cuppelation Gold only 0.02%
Inductively coupled plasma
spectroscopy (ICP)
Complete analysis 0.10%
X-ray fluorescence
spectroscopy (XRF)
Complete analysis 0.1–0.5%
Acid test (touchstone
method)
Gold only 1–2%
Electronic pen Gold only 4–8%
Density Gold only Low

35. Repeatability 5 Sec on 18K
72.5
73
73.5
74
74.5
75
75.5
76
76.5
77
77.5
-3 2 7 12 17 22
Reading #
%Au
Delta Au Competitive Inst Cert.
Repeatability 20 Sec on 18K
72.5
73
73.5
74
74.5
75
75.5
76
76.5
77
77.5
-3 2 7 12 17 22
Reading #
%Au
Delta Au Competitive Inst Cert.
repeatability 5 sec for 18K Au
70
71
72
73
74
75
76
77
78
79
80
-3 2 7 12 17 22
reading Nr.
Au%GoldXpert
Au Gold Xpert Certified Value
repeatability 10 sec for 18K Au
70
71
72
73
74
75
76
77
78
79
80
-3 2 7 12 17 22
reading Nr.
Au%GoldXpert
Au Gold Xpert Certified Value

36. ¡ On-site demonstration
¡ Short-term trial
− Make sure you have at least one certified reference material
¡ Leasing and/or rent-to-own options?
¡ Warranty? Service plans?
¡ Industry references
¡ Beware cheap knockoffs
Choosing an XRF Analyzer

37. Olympus is a registered trademark, and Vanta is a trademark of Olympus Corporation.