GEM KNOWLEDGE · LABORATORY NOTES
Copper (Michigan)
Copper in altered volcanic rock from Michigan’s Upper Peninsula, with composition and host rock consistent with that region.
Sample: 1563 (#3 copper disk) · Completed: March 18, 2026.
Finding: Copper containing minor iron and traces of silver, cobalt, and selenium, in altered iron-rich tholeiitic basalt.
The researcher considers both the copper composition and associated rock typical of the Upper Peninsula. Alteration prevents determining whether olivine was originally present.
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These results are the property of Soul Body Gems, Alexander Falster, and the Maine Mineral & Gem Museum. Any mention requires full acknowledgment.
Read the report findings and table as text
Sample 1563 (#3 copper disk), submitted by Soul Body Gems, completed March 18, 2026. A Bruker Titan X-ray fluorescence spectrometer operated at 10, 25, and 50 kV. A Bruker D2-Phaser X-ray diffractometer operated at 30 kV and 10 mA. Figure 1 shows a specimen of 3.7 cm maximum dimension.
| Element | Wt.% |
|---|---|
| Cobalt | 0.06 |
| Copper | 99.1 |
| Iron | 0.7 |
| Selenium | 0.001 |
| Silver | 0.02 |
Summary: Copper typical of Michigan’s Upper Peninsula, containing silver, selenium, and cobalt. Matrix is altered iron-rich tholeiitic basalt; alteration obscures whether olivine was present. Regional rocks include basalts extending into iron-rich andesites. The copper and host rock match this region. The researcher relates this source to copper used by Copper Culture peoples as far back as 6,500 years. Page 2 contains the March 18, 2026 date and signature.
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The following text and tables are transcribed from the original laboratory document. Figure captions identify the report images; the laboratory interpretations and limitations are preserved.
Laboratory report 1
Analytical Result Report
Sample id: 1563 (#3 copper disk)
Submitted by: Soul Body Gems
Date completed: 3-18-2026
Operating conditions: A Bruker Titan X-ray fluorescence spectrometer was used and operated at 10, 25 and 50 kV.
A Bruker D2-Phaser X-ray diffractometer was also used and operated at 30 kV and 10 mA.
Fig. 1: Photograph of the specimen. 3.7 cm maximum dimension.
Table 1: Major and minor elemental composition of the material, in wt. %.
| Element | Reported value |
|---|---|
| Cobalt | 0.06 |
| Copper | 99.1 |
| Iron | 0.7 |
| Selenium | 0.001 |
| Silver | 0.02 |
Summary of findings: This is an interesting specimen (Fig. 1). The copper is typical for the upper Peninsula of Michigan. It contains noticeable silver content as well as selenium and cobalt. I have done a lot of work on this copper. The matrix is altered iron-rich tholeiitic basalt. I can’t tell if any olivine has been present anymore due to the alteration. The typical rocks in the UP are various basalts and can range into iron-rich andesites. Thus, the copper’s composition and the associated country rock match what occurs there. This is also the source of the copper that was used by the Copper Culture people back to 6500 years.
Date: 3-18-2026 Signature