GEM KNOWLEDGE · LABORATORY NOTES
Blue Scheelite
Material marketed as “Blue Scheelite” and supplied as a newer find from Turkey was submitted for analysis. The name emphasizes a mineral that makes up only a small part of the tested piece.
Finding: The specimen is predominantly dolomite. The laboratory found scheelite grains, but estimated their contribution at well below 1% of the sample.
The name and the testing
The miner used the name “Blue Scheelite” and, in conversation, described the material as containing calcite and dolomite without testing it. Our submitted specimen tested predominantly as dolomite with scheelite grains present at well below 1%. The report did not identify calcite in this analyzed piece. That is why the name and informal description are presented as history rather than a composition guarantee.
What the report shows
Sample 92854 (#14) is an approximately 11 cm banded specimen. The laboratory used electron imaging, elemental analysis, and X-ray mapping. It described an assemblage compatible with a hydrothermal vein setting, while discussing a skarn setting as another possibility. Its reported trace tungsten does not make scheelite the dominant material.
Turkey and a trade introduction around 2018 are supplied background, not independently verified by this laboratory report. The findings apply to the submitted piece; other material sold as Blue Scheelite may differ.
View the original report
Select any page to enlarge it. 4 pages, in report order.
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 images 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 spectral analysis of spot 1 in Fig. 2. (dolomite)
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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. 4: Backscattered electron images 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. 5: Energy dispersive spectral analysis of spot 1 in Fig. 4. (scheelite)
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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. 6: X-ray maps of the area shown in Fig. 2: Magnesium-red, calcium-green, iron-blue. Iron is shown on the left iamges as well but to show it more clearly, it is shown by itself on the right once more.
Read the report as text
This text is transcribed from the laboratory report so the findings and figure captions can be read without opening the page images. The images remain available above for visual details.
Laboratory report
Analytical Result Report Sample id: 92854 (#14) Submitted by: K. Bitner Date submitted: Feb. 14, 2022. Date completed: March 7, 2022. Operating conditions: An AMRAY 1830 SEM operated at 25 kV acceleration potential, 26 mm working distance, 15 degrees sample tilt, coated with 250 Å carbon. Using the X-ray fluorescence attachment with 35 kV potential in conjunction with the EDS system. Fig. 1: Photograph of the specimen. 11 cm maximum dimensions. Fig. 2: Backscattered electron images of the specimen. Fig. 3: Energy dispersive spectral analysis of spot 1 in Fig. 2. (dolomite) Fig. 4: Backscattered electron images of the specimen. Fig. 5: Energy dispersive spectral analysis of spot 1 in Fig. 4. (scheelite) Fig. 6: X-ray maps of the area shown in Fig. 2: Magnesium-red, calcium-green, iron-blue. Iron is shown on the left iamges as well but to show it more clearly, it is shown by itself on the right once more. Table 1: Minor and trace element composition of the specimen. (in wt. %). Iron 0.92 Manganese 0.02 Titanium 0.01 Tungsten 0.12 Summary of findings: This specimen (Fig. 1) is composed dominantly of dolomite (Figs. 2 and 3). The material is clearly banded (Figs. 1 and 6) which is part caused by iron but by the grain size. This is likely derived from a hydrothermal vein type assemblage where such banding is common. Another possibility is a skarn body where banding is also common but the differing grain sizes are not typical for that environment whereas scheelite would fir in either case. There are some bright grains visible in backscattered electron images (Figs. 2, 4 and 5), they are scheelite! However, the scheelite contribution of the sample is well below 1 %! (Table 1). Date: March 5, 2022 Signature
