GEM KNOWLEDGE · LABORATORY NOTES
Purple Jade
A lilac 5 cm heart sold as Purple Jade was examined to see what minerals actually make up the stone.
Finding: Sample 92930 (#14), completed August 2, 2022, contains jadeite, but also substantial albite, orthoclase, quartz and mica. The laboratory cautioned that calling the entire mixed material “jadeite” may overstate the amount of jadeite present.
Energy-dispersive analysis alone was inconclusive; X-ray diffraction and mapped domains helped resolve the mineral mixture. The report notes that the proportions might vary within the source material. Its document does not name a locality, and this result applies to the tested heart.
View the original report
Select a page to enlarge it. 5 pages; findings are summarized in accessible text above.
Report images © Soul Body Gems, Alexander Falster and the Maine Mineral & Gem Museum. Please acknowledge all three when referring to these results. Findings apply to the specimen examined.
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 (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 spectral analysis of spot 2 in Fig. 2 (mica group)
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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 3 in Fig. 2 (alkali feldspar)
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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 5: X-ray diffractogram of a portion of the material. Reference patterns are indicated for quartz, jadeite, orthoclase, albite, and a mica species, here phlogopite.
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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. 7: Energy dispersive spectral analysis of a domain rich in jadeite.
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: 92930 (#14, lilac heart)
Submitted by: K. Bitner
Date submitted: July 14, 2022.
Date completed: July 31, 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. A Bruker D2 Phaser X-ray diffractometer was used and operated at 30 kV and 10 mA.
Fig. 1: Photograph of the specimen. 5 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 (quartz)
Fig. 4: Energy dispersive spectral analysis of spot 2 in Fig. 2 (mica group)
Fig. 4: Energy dispersive spectral analysis of spot 3 in Fig. 2 (alkali feldspar)
Fig 5: X-ray diffractogram of a portion of the material. Reference patterns are indicated for quartz, jadeite, orthoclase, albite, and a mica species, here phlogopite.
Fig. 6: X-ray of the area shown in Fig. 2. sodium: yellow, potassium: purple.
Fig. 7: Energy dispersive spectral analysis of a domain rich in jadeite.
Table 1: Minor and trace element composition of the specimen. (in wt. %).
| Element | Reported value |
|---|---|
| Barium | 0.03 |
| Calcium | 0.13 |
| Iron | 0.86 |
| Strontium | 0.07 |
| Zirconium | 0.16 |
Summary of findings: This specimen (Fig. 1) is intriguing! By Energy dispersive analyses, the results were not conclusive. Feldspars and jadeite both occur and are intimately intergrown (Fig. 6) but X-ray diffraction could resolve that albite, orthoclase, quartz as well as jadeite are present (Figs. 2 to 5). A mica species is present as well, note the typical low angle reflection in Fig. 6. Chemically, the mica is closest to muscovite though aluminum appears slightly low. It might be a little bit of a stretch to call the material jadeite since so much other mineral material is present, but it does contain at least some jadeite (Figs. 5, 6 and 7). It is also possible that there is some variability at this location with areas higher or lower in jadeite.
Date: Aug. 2, 2022 Signature