GEM KNOWLEDGE · LABORATORY NOTES
Aquamarine (India)
A gray specimen supplied from India was sent for testing under a beryl identification. The report supports beryl, while the aquamarine label needs a separate color qualification.
Finding: The aluminum-to-silicon ratio, measured density of 2.72 g/cm³, and uniaxial negative optical character were consistent with beryl. The researcher specifically noted its unusual gray color. Iron, magnesium, and sodium were reported as minor components.
Why the names differ: Aquamarine is the blue to blue-green gem variety of beryl. This report establishes beryl in this gray sample; it does not describe it as blue aquamarine. The India locality is supplied provenance rather than a result of the analysis.
Tested specimen: Sample 92905 (#5), approximately 3 cm; report completed April 20, 2022. One figure caption appears inconsistent with the report’s beryl conclusion; the original pages are shown without alteration to that text.
View the original report
Select a page to enlarge it. Two pages; findings are summarized in accessible text above.
The tested identification is Beryl (India).
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 spectral analysis of spot 1 in Fig. 2 (silia-rich rhyolitic rock)
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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)
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: 92905 (#5) ‘beryl’
Submitted by: K. Bitner
Date submitted: April 4, 2022.
Date completed: April 20, 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. 3 cm maximum dimensions.
Fig. 2: Backscattered electron image of an area of the specimen.
Fig. 3: Energy dispersive spectral analysis of spot 1 in Fig. 2 (silia-rich rhyolitic rock)
Fig. 4: Energy dispersive spectral analysis of spot 2 in Fig. 2)
Table 1: Minor and trace element composition of the specimen. (in wt. %).
| Element | Reported value |
|---|---|
| Iron | 0.65 |
| Magnesium | 0.55 |
| Manganese | 0.03 |
| Sodium | 0.51 |
| Titanium | 0.01 |
Summary of findings: This specimen (Fig. 1) is a very interesting one. Chemically, it is an aluminum silicate (Figs. 2 and 3) with the aluminum:silicon ratio at 1:3. The specimen contains some magnesium and sodium plus iron as main minor components. The density was determined to be 2.72 g/cm3 and optically it is uniaxial negative. This is all consistent with beryl. It is a little unusual for its gray color.
Date: April 20, 2022 Signature