GEM KNOWLEDGE · LABORATORY NOTES
Noreena Jasper (Australia)
An Australian Noreena Jasper palm stone examined for its banding, fracture fillings and color.
Finding: Sample 9145, completed July 16, 2020, was interpreted as silicified mudstone or silicified volcanic rock, possibly a mixture. Fractures contain hematite or goethite, and the specimen had a weak magnetic response suggesting a little magnetite.
The report describes late Archean material and notes that the brown coloration may have developed through later oxidation. The findings apply to this palm stone; Noreena Jasper is a locality market name rather than a mineral species.
View the original report
Select a page to enlarge it. 2 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. 1: Backscattered electron image (Noreena jasper)
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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. 2: Energy dispersive spectrum of spot 1 in Fig. 1. (silicified mudstone or silicified volcanic 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. 2: Energy dispersive spectrum of spot 2 in Fig. 1. (silicified mudstone or silicified volcanic 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. 3: Energy dispersive spectrum of spot 3 in Fig. 1. (silicified mudstone or silicified volcanic rock).
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: 9145 (#2 Noreena jasper palm)
Submitted by: K. Bitner
Date submitted: July 13, 2020
Date completed: July 16, 2020
Operating conditions: JEOL JSM-6400 operated at 25 kV acceleration potential, 15 mm working distance, 15 degrees sample tilt, coated with 250 Å carbon. Using the X-ray fluorescence attachment with 35kv potental in conjunction with the EDS system.
Fig. 1: Backscattered electron image (Noreena jasper)
Fig. 2: Energy dispersive spectrum of spot 1 in Fig. 1. (silicified mudstone or silicified volcanic rock).
Fig. 2: Energy dispersive spectrum of spot 2 in Fig. 1. (silicified mudstone or silicified volcanic rock).
Fig. 3: Energy dispersive spectrum of spot 3 in Fig. 1. (silicified mudstone or silicified volcanic rock).
Summary of findings: This is a very old specimen, late Archaean. It is essentially a silicified mudstone of silicified volcanic rock, possibly a mixture of each (Figs. 1-3). The fractures are filled with hematite or goethite and the color is a result of trivalent iron which imparts the tan to brown colors. Total iron content is around 7000-8200 ppm. Manganese is very low, only about 120 ppm. The weak magnetic response suggests that a little magnetite is present as well, thus a little divalent iron is left. At the end of the Archaean, only very little free oxygen was present, it is very possible that the brown colors are the result of much later oxidation.
Date: July 16 ,2020 Signature