GEM KNOWLEDGE · LABORATORY NOTES
Black Diamond
Cut black stones submitted as carbonados were examined using X-ray fluorescence, micro-Raman spectroscopy, density and hardness testing.
What our testing found
- The Raman spectrum matched diamond, and the analyst concluded that the submitted stones are genuine.
- Measured density was approximately 3.51 g/cm³.
- The stones scratched corundum, indicating Mohs hardness greater than 9.
- The measured minor and trace elements were described as typical for carbonados.
This report confirms diamond in these specimens. It does not separately establish a geographic origin or provide a treatment assessment.
Sample 155, completed December 31, 2025.
Also listed under: Black Diamond · Carbonados. These entries share the same test report.
View the original test results
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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.
Understanding the report figures
Use this guide alongside the written findings and the original report transcript. It explains the purpose of each analytical figure and preserves the laboratory’s own figure labels. The interpretations apply to the tested specimen; signals alone do not establish the identity of every similar-looking stone.
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Raman spectrum: This spectrum records how the material responds to laser light. The pattern is used to compare the tested material with reference spectra.
Laboratory figure caption: Fig. 2: Raman spectrum of the stones.
Read the complete report as text
Analytical Result Report
Sample id: 155 (carbonados, cut)
Submitted by: Soul Body Gems
Date completed: 12-31-2025
Operating conditions: A Bruker Titan X-ray fluorescence spectrometer was used and operated at 10, 25 and 50 kV.
In addition, a microRaman RL-785 was used in the study.
Fig. 1: Photograph of the specimens. 9 mm maximum dimension
Table 1: Minor and trace elements in the specimens, in ppm.
Chromium
67
Iron
279
Manganese
30
Nickel
45
Titanium
58
Fig. 2: Raman spectrum of the stones.
Summary of findings: These are interesting specimens (Fig.1)! Density determination is around 3.51 g/cm3. The stones do scratch corundum thus the Mohs hardness is greater than 9. The elements heavier than magnesium are shown in Table 1 and they a re typical for carbonados. The Raman spectrum (Fig. 2) is a match for diamond, thus the stones are genuine.
Date: 12-31-2025 Signature
Read the original laboratory report as text
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: 155 (carbonados, cut)
Submitted by: Soul Body Gems
Date completed: 12-31-2025
Operating conditions: A Bruker Titan X-ray fluorescence spectrometer was used and operated at 10, 25 and 50 kV.
In addition, a microRaman RL-785 was used in the study.
Fig. 1: Photograph of the specimens. 9 mm maximum dimension
Table 1: Minor and trace elements in the specimens, in ppm.
| Element | Reported value |
|---|---|
| Chromium | 67 |
| Iron | 279 |
| Manganese | 30 |
| Nickel | 45 |
| Titanium | 58 |
Fig. 2: Raman spectrum of the stones.
Summary of findings: These are interesting specimens (Fig.1)! Density determination is around 3.51 g/cm3. The stones do scratch corundum thus the Mohs hardness is greater than 9. The elements heavier than magnesium are shown in Table 1 and they a re typical for carbonados. The Raman spectrum (Fig. 2) is a match for diamond, thus the stones are genuine.
Date: 12-31-2025 Signature