GEM KNOWLEDGE · LABORATORY NOTES
Lepidolite Tourmaline
The photograph shows Lepidolite Tourmaline towers from our collection. The laboratory tested a sphere, sample 10514; the original sphere photograph appears in the report below.
A unique Brazilian find bringing together green tourmaline and contrasting mica and feldspar.
Tested specimen: Sample 10514 (recent package #2) · Report completed: March 21, 2024.
Identification: Green elbaite tourmaline, lepidolite, muscovite, and albite.
Locality: Brazil, according to Soul Body Gems sourcing information.
What the testing revealed
The report identifies both lepidolite and muscovite in this specimen. The green elbaite tourmaline contains more iron than manganese, and the plagioclase feldspar is albite.
The researcher describes the specimen as derived from a fractionated granitic pegmatite. The lepidolite is slightly more fractionated than the muscovite, particularly in its rubidium content.
View the original test results
Select a page to enlarge it.
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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Electron microscope image: This view shows small-scale regions selected for analysis. Its brightness contrast helps distinguish regions with different compositions; it is not a photograph of their natural colors. Numbered spots connect this view to the analyses listed in the report.
Laboratory figure caption: Fig.2: Backscattered electron image of an area of the specimen.
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Elemental spectrum: The peaks record characteristic X-ray signals from elements in the analyzed spot or area. This is an analysis of that location, not automatically of the entire specimen. Any mineral identification or uncertainty named in the laboratory caption is retained below.
Laboratory figure caption: Fig. 3: Energy dispersive spectrum of spot 1 in Fig. 2 (tourmaline - elbaite)
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Elemental spectrum: The peaks record characteristic X-ray signals from elements in the analyzed spot or area. This is an analysis of that location, not automatically of the entire specimen. Any mineral identification or uncertainty named in the laboratory caption is retained below.
Laboratory figure caption: Fig. 4: Energy dispersive spectrum of spot 2 in Fig. 2 (lepidolite)
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Elemental spectrum: The peaks record characteristic X-ray signals from elements in the analyzed spot or area. This is an analysis of that location, not automatically of the entire specimen. Any mineral identification or uncertainty named in the laboratory caption is retained below.
Laboratory figure caption: Fig. 6: Energy dispersive spectrum of spot 3 in Fig. 2 (muscovite)
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Elemental spectrum: The peaks record characteristic X-ray signals from elements in the analyzed spot or area. This is an analysis of that location, not automatically of the entire specimen. Any mineral identification or uncertainty named in the laboratory caption is retained below.
Laboratory figure caption: Fig. 7: Energy dispersive spectrum of spot 4 in Fig. 2 (albite)
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Element map: This map shows where the named elements occur within the analyzed area. Its colors represent the laboratory’s selected element channels, rather than the specimen’s visible colors. The caption below preserves any color key or distribution noted by the laboratory.
Laboratory figure caption: Fig. 8: X-ray map of the area shown in Fig. 2. Sodium: yellow, potassium: purple, iron: green.
Read the report findings and table as text
Analytical Result Report. Sample id: 10514 (recent package #2). Submitted by Soul Body Gems. Date completed: March 21, 2024.
Operating conditions: An AMRAY 1830 scanning electron microscope operated at 25 kV acceleration potential, 24 mm working distance, and 0 degrees sample tilt. The sample was coated with 250 Å carbon. The attached X-ray fluorescence unit operated at 30 kV. A BRUKER Titan X-ray fluorescence spectrometer was also used, operated for 30 seconds at 50, 25, and 10 kV.
- Figure 1: Photograph of the sphere, approximately 60 mm maximum dimension.
- Figure 2: Backscattered electron image.
- Figure 3: Energy-dispersive spectrum, spot 1, tourmaline—elbaite.
- Figure 4: Energy-dispersive spectrum, spot 2, lepidolite.
- Figure 6: Energy-dispersive spectrum, spot 3, muscovite.
- Figure 7: Energy-dispersive spectrum, spot 4, albite.
- Figure 8: X-ray map with sodium in yellow, potassium in purple, and iron in green.
| Element | Lepidolite | Muscovite |
|---|---|---|
| Iron | 0.04 | 0.22 |
| Manganese | 0.32 | 0.12 |
| Rubidium | 0.48 | 0.34 |
| Sodium | 0.77 | 0.65 |
Summary: The green tourmaline (elbaite) contains more iron than manganese. Both lepidolite and muscovite occur in the specimen. The lepidolite is a little more fractionated than the muscovite, notably in rubidium content. The plagioclase is albite. The specimen is derived from a fractionated granitic pegmatite. The report concludes with the March 21, 2024 date and 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: 10514 (recent package #2)
Submitted by: Soul Body Gems
Date completed: 3-21-2024
Operating conditions: An AMRAY 1830 SEM operated at 25 kV acceleration potential, 24 mm working distance, 0 degrees sample tilt, coated with 250 Å carbon, and also using the attached XRF unit operated at 30 kV.
A BRUKER Titan X-ray fluorescence spectrometer was also used and operated for 30 seconds at 50, 25, and 10 kV.
Fig. 1: Photograph of the specimen. Approximately 60 mm maximum dimension.
Fig.2: Backscattered electron image of an area of the specimen.
Fig. 3: Energy dispersive spectrum of spot 1 in Fig. 2 (tourmaline - elbaite)
Fig. 4: Energy dispersive spectrum of spot 2 in Fig. 2 (lepidolite)
Fig. 6: Energy dispersive spectrum of spot 3 in Fig. 2 (muscovite)
Fig. 7: Energy dispersive spectrum of spot 4 in Fig. 2 (albite)
Fig. 8: X-ray map of the area shown in Fig. 2. Sodium: yellow, potassium: purple, iron: green.
Table 1: Trace and minor elements in lepidolite and muscovite in the specimen.
| lepidolite | muscovite | |
|---|---|---|
| Iron | 0.04 | 0.22 |
| Manganese | 0.32 | 0.12 |
| Rubidium | 0.48 | 0.34 |
| Sodium | 0.77 | 0.65 |
Summary of findings: This specimen (Fig. 1) is very interesting one: the tourmaline (elbaite) (Figs. 2, 3 and 8) is green and contains more iron than manganese. Both lepidolite (Figs. 2 and 4) and muscovite (Figs. 2 and 5) occur in the specimen. Table 1 shows the differences in trace element and minor elements. The lepidolite overall is a little more fractionated than the muscovite, notably seen in the rubidium content. The plagioclase is an albite (Figs. 2 and 7). This sample was derived from a fractionated granitic pegmatite.
Date: March 21, 2024 Signature