GEM KNOWLEDGE · LABORATORY NOTES
Feldspar Tourmaline
Potassium feldspar, which the researcher notes could be described as orthoclase, associated with dark elbaite tourmaline containing a small liddicoatite component.
Tested specimen: 10624 (#13) · Report completed: September 10, 2024
Supplied locality: Supplied from the Pakistan–Afghanistan region; exact country and mine unknown. Locality is supplied background, not independently established by the analysis.
What the report shows
The finding is elbaite with a small liddicoatite component, not a definitive identification of the entire tourmaline as liddicoatite. The printed sample number is reused on other reports; this report is distinguished by its material, specimen number and date.
Also listed as: Tourmaline Feldspar · Feldspar Tourmaline
View the original report
Select any report page to enlarge it. A text transcript is available below.
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.
-
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.
-
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 (potassium feldspar)
-
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 (tourmaline group)
Read the report transcript
Analytical Result Report
Sample id: 10624 (#13 feldspar w tourmaline)
Submitted by: Soul Body Gems
Date completed: 9-10-2024
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 specimen. Approximately 35 mm maximum dimension.
Fig.2: Backscattered electron image of an area of the specimen.
Fig. 3: Energy dispersive spectrum of spot 1 in Fig. 2 (potassium feldspar)
Fig. 4: Energy dispersive spectrum of spot 2 in Fig. 2 (tourmaline group)
Summary of findings: This specimen (Fig. 1) is composed of a potassium feldspar (Figs. 2 and 3), I don’t see noticeable exsolution lamellae so I keep it as potassium feldspar, orthoclase could also be used. The associated tourmaline is a dark elbaite with small liddicoatite component (Figs. 2 and 4).
Date: 9-10-2024 Signature