GEM KNOWLEDGE · LABORATORY NOTES
Gobi Agate
The tested Gobi Agate specimen is chalcedony, with visible layering and pink color attributed mainly to a little trivalent iron, likely tiny hematite inclusions.
Tested specimen: 1206 (#5 Gobi stone) · Report completed: December 22, 2024
Key finding: The report identifies quartz in the analyzed spots and concludes that this specimen is chalcedony. Its layered texture is visible in the sample and electron images.
What the report means
The researcher discusses several possible origins for the tubular or branch-like form, including replacement of plant material, filling of burrows, or filling of tubes in volcanic rock. The report does not establish which occurred. “Gobi Agate” is the market name; the tested material is chalcedony.
View the original test results
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These results apply to the specimen tested. Report images are property of Soul Body Gems, Alexander Falster, and the Maine Mineral & Gem Museum; please acknowledge all three when referring to these results.
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. (quartz)
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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. (quartz)
Read the report findings as text
Sample 1206 (#5 Gobi stone), completed December 22, 2024. Figure 1 photographs a specimen with maximum dimension 6 cm. Figure 2 is a backscattered electron image; Figures 3 and 4 are energy-dispersive spectra of quartz. The summary identifies chalcedony, notes its layering, and attributes the pink color mainly to minor trivalent iron, likely tiny hematite inclusions. Several origins for its shape are presented as possibilities.
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: 1206 (#5 Gobi stone)
Submitted by: Soul Body Gems
Date completed: 12-22-2024
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.
Fig. 1: Photograph of the specimens. 6cm maximum dimensions.
Fig.2: Backscattered electron image of an area of the specimen.
Fig. 3: Energy dispersive spectrum of spot 1 in Fig. 2. (quartz)
Fig. 4: Energy dispersive spectrum of spot 2 in Fig. 2. (quartz)
Summary of findings: This specimen (Fig. 1) is chalcedony (Figs. 2-4). The pink color is mainly caused by a small amount of iron, in the trivalent state, likely as hematite in form of tiny inclusions. The material clearly shows some layering (Figs. 1 and 2). It is possible that this is a replacement of plant matter, twigs or branches but it could also have formed as a filling material of burrows or fill of tubes in volcanic rock.
Date: 12-22-2024 Signature