GEM KNOWLEDGE · LABORATORY NOTES
Sodalite (India)
A sphere marketed as sodalite reveals a complex rock under testing.
What the report found: The laboratory identified sodalite and albite together with nepheline, magnesian iron-bearing calcite, biotite–phlogopite series mica and ilmenite. Quartz was not identified.
The assemblage is consistent with an alkaline, silica-poor intrusive setting. “Sodalite sphere” is a useful retail description, but it does not mean the entire sphere is a single pure mineral.
View the original report
Select a page to enlarge it. The text transcript below provides another way to read the findings.
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. 1: Backscattered electron image (sodalite sphere)
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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. 2: Energy dispersive spectrum of spot 1 in Fig. 1. (magnesian ferroan calcite with minor manganese contribution)
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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 2 in Fig. 1. (biotite-phlogopite)
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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 3 in Fig. 1. (ilmenite)
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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. 5: Energy dispersive spectrum of spot 4 in Fig. 1. (nepheline)
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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. 6: Backscattered electron image (sodalite sphere)
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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 6 in Fig. 6. (albite)
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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. 8: Backscattered electron image (sodalite sphere)
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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. 9: Energy dispersive spectrum of spot 3 in Fig. 8. (sodalite)
Read the report as text
Transcript of the original analytical report, including figure descriptions and findings.
Analytical Result Report
Sample id: 9147 (sodalite sphere)
Submitted by: K.Bitner
Date submitted: July 31, 2020
Date completed: August 5, 2020
Operating conditions: JEOL JSM-6400 operated at 25 kV acceleration potential, 15 mm working distance, 15 degrees
sample tilt, coated with 250 Å carbon. Using the X-ray fluorescence attachment with 35kv potental in conjunction with
the EDS system.
Fig. 1: Backscattered electron image (sodalite sphere)
Fig. 2: Energy dispersive spectrum of spot 1 in Fig. 1. (magnesian ferroan calcite with minor manganese contribution)
Fig. 3: Energy dispersive spectrum of spot 2 in Fig. 1. (biotite-phlogopite)
Fig. 4: Energy dispersive spectrum of spot 3 in Fig. 1. (ilmenite)
)
Fig. 5: Energy dispersive spectrum of spot 4 in Fig. 1. (nepheline)
Fig. 6: Backscattered electron image (sodalite sphere)
Fig. 7: Energy dispersive spectrum of spot 6 in Fig. 6. (albite)
Fig. 8: Backscattered electron image (sodalite sphere)
Fig. 9: Energy dispersive spectrum of spot 3 in Fig. 8. (sodalite)
Summary of findings: This is a very complex specimen! It stems from an alkalic intrusive, silica deficient, thus no quartz
but instead feldspars (Figs. 1, 5, 6 and 7) and feldspathoids such as nepheline and sodalite (Figs. 8 and 9) are present. In
this case, we see albite, sodalite. Associated minerals include a magnesian ferroan calcite (Figs. 1 and 2) , biotite-
phlogopite series micas (Figs. 1 and 3) , ilmenite (Figs. 1 and 4). Alkalic complexes frequently harbor carbonatite bodies,
the presence of carbonates in this sample suggest that this location could have been one of those bodies.
Date: August 5 ,2020 Signature