GEM KNOWLEDGE · LABORATORY NOTES
Opal (White)
Chemistry fits opal. X-ray diffraction showed an amorphous component together with quartz and some tridymite and cristobalite lines, interpreted as opal progressing toward crystallinity.
Collection background: Kazakhstan. This sourcing information is supplied by Soul Body Gems.
What the testing found
- Chemistry fits opal. X-ray diffraction showed an amorphous component together with quartz and some tridymite and cristobalite lines, interpreted as opal progressing toward crystallinity.
- Report sample 1151, completed March 26, 2025.
Also listed as Cacholong Opal · Opal (White); these entries share the same report.
View the original test results
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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. (looks right for opal)
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Diffraction scan: This scan helps identify crystalline minerals by comparing the measured pattern with reference patterns. The laboratory interpretation explains which minerals the comparison supports.
Laboratory figure caption: Fig. 4: X-ray diffraction scan of the specimen with matching stick patterns for quartz, cristobalite and tridymite.
Read the complete report as text
Analytical Result Report
Sample id: 1151 (#6 opal)
Submitted by: Soul Body Gems
Date completed: 3-26-2025
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 D2 Phaser X-ray diffractometer was also used in the study and operated at 30 kV and 10 mA.
Photograph of the specimen. Approximately 2.8 cm maximum dimension,
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Fig.2: Backscattered electron image of an area of the specimen.
Fig. 3: Energy dispersive spectrum of spot 1 in Fig. 2. (looks right for opal)
Fig. 4: X-ray diffraction scan of the specimen with matching stick patterns for quartz, cristobalite and tridymite.
Summary of findings: This specimen (Fig. 1) is a pretty one, very clean white. Chemically, it fits opal (Figs. 2 and 3). An X-ray diffraction scan has also been run, and it shows the amorphous hump plus some quartz lines as well. Opal will crystallize fairly rapidly, geologically speaking, it usually goes via a cristobalite and tridymite type and then to quartz. This specimen shows some of the tridymite lines and less intensely, some cristobalite lines. Thus, it is opal that is on its way to become crystalline.
Date: 3-26-2025 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: 1151 (#6 opal)
Submitted by: Soul Body Gems
Date completed: 3-26-2025
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 D2 Phaser X-ray diffractometer was also used in the study and operated at 30 kV and 10 mA.
Photograph of the specimen. Approximately 2.8 cm maximum dimension,
11
Fig.2: Backscattered electron image of an area of the specimen.
Fig. 3: Energy dispersive spectrum of spot 1 in Fig. 2. (looks right for opal)
Fig. 4: X-ray diffraction scan of the specimen with matching stick patterns for quartz, cristobalite and tridymite.
Summary of findings: This specimen (Fig. 1) is a pretty one, very clean white. Chemically, it fits opal (Figs. 2 and 3). An X-ray diffraction scan has also been run, and it shows the amorphous hump plus some quartz lines as well. Opal will crystallize fairly rapidly, geologically speaking, it usually goes via a cristobalite and tridymite type and then to quartz. This specimen shows some of the tridymite lines and less intensely, some cristobalite lines. Thus, it is opal that is on its way to become crystalline.
Date: 3-26-2025 Signature