GEM KNOWLEDGE · LABORATORY NOTES
Mangano Calcite (Peru)
A calcite specimen with a striking red response under ultraviolet light and a dark included mass.
Tested specimen: 92846 (#5) · Report completed: February 25, 2022
Key finding: Testing identified manganoan calcite and a dark mass of sphalerite. The report attributes the strong red UV fluorescence to manganese in the absence of detectable iron in the tested calcite.
What the report means
The report considers a hydrothermal vein association likely. Peru is the provenance supplied by Soul Body Gems, not a locality established by the analysis. UV response and phase distribution were documented for this specimen. Also see Pink Mangano Calcite.
View the original test results
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The images reproduce the laboratory report for the specimen named above.
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. (manganoan calcite)
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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 spectral analysis of spot 2 in Fig. 2. (sphalerite)
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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. 5: Backscattered electron image of the area shown in Fig. 2. Manganese: blue, zinc: yellow..
Read the report as text
This transcription makes the laboratory findings, figure captions, and table values available without opening the page images. Refer to the original images above for visual details.
Laboratory report
Analytical Result Report Sample id: 92846 (#5) Submitted by: K. Bitner Date submitted: Feb. 14, 2022. Date completed: Feb. 25, 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. 6.5cm maximum dimension. Left: daylight, riht: UV light showing strong red fluorescence Fig. 2: Backscattered electron images of the specimen. Fig. 3: Energy dispersive spectral analysis of spot 1 in Fig. 2. (manganoan calcite) Fig. 4: Energy dispersive spectral analysis of spot 2 in Fig. 2. (sphalerite) Fig. 5: Backscattered electron image of the area shown in Fig. 2. Manganese: blue, zinc: yellow.. Table 1: Minor and trace element composition of the specimen. (in wt. %). Iron nd Magnesium 1.1 Manganese 5.7 Zinc 0.2 Summary of findings: This specimen (Fig. 1) is a manganoan calcite (Figs. 2 and 3, Table 1). The lack of iron permitted strong UV response caused by manganese shown in Fig. 1. Manganese is distributed a little patchy which is noticeable in Fig. 5. A dark mass of sphalerite is present in the specimen (Figs. 2 and 4). The sphalerite is very clean! This is likely a specimen from a hydrothermal vein type assemblage. A very intriguing specimen! Date: February 25, 2022 Signature