GEM KNOWLEDGE · LABORATORY NOTES
Lavender Fluorite
A lavender and white fluorite from a mine near the Brazil–Argentina border.
What the report found: Fluorite with approximately 120 ppm yttrium in the purple zone and 300 ppm in the white/colorless zone.
The boundary between purple and white is rich in fluid and solid inclusions, with calcite apparently dominant. A sharper boundary within the purple zone has a thin quartz coating. The white area formed later and appears to have grown rapidly, leaving elongate crystals and abundant inclusions.
The mine locality is supplied from our sourcing records; the report analyzes the submitted fluorite rather than verifying its geographic origin. It is fluorite with trace yttrium, not a separate mineral species named “yttrium fluorite.” The green specimen is separately tested and has a higher yttrium concentration.
View the original report
Select a page to enlarge it. A text transcript appears 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 the white to colorless portion of the fluorite
-
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 area 1 in Fig. 2
-
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. 4: Backscattered electron image of the purple portion of the fluorite
-
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. 5: Energy dispersive spectrum of area 1 in Fig. 4
-
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. 6: Backscattered electron image of the cloudy portion of the fluorite.
-
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 spectrum of area 1 in Fig. 6. Scaled to show the trace eleemnts Y and Yb’s presence.
Read the report as text
Analytical Result Report Sample id: 9023 Fluorite Submitted by: Kathreen Bitner Date submitted: May 19, 2020 Date completed: May 21, 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 attacement with 35kv potental in conjunction with the EDS system Fig 1: Photomicrographs showing boundary from purple to white (left: 2.5 mm across, middle: 0.7 mm across, right: 0.7 mm across. The right image is a thinner boundary within the purple fluorite and the boundary is coated by thing quartz particles wheres the diffuse boundary of the purple to white is rich in fluid and solid inclusions (calcite). Fig. 2: Backscattered electron image of the white to colorless portion of the fluorite Fig. 3: Energy dispersive spectrum of area 1 in Fig. 2 Fig. 4: Backscattered electron image of the purple portion of the fluorite Fig. 5: Energy dispersive spectrum of area 1 in Fig. 4 Fig. 6: Backscattered electron image of the cloudy portion of the fluorite. Fig. 7: Energy dispersive spectrum of area 1 in Fig. 6. Scaled to show the trace eleemnts Y and Yb’s presence. Fig. 8: Photograph of the white to colorlesss portion, arrows indicate radiating elongate fluorite grains growth direction. Summary of findings: A very interesting specimen! There are two types of distinct boundaries: a diffuse one between the purple and white/colorless parts and a thinner, sharp one within the purple fluorite (Fig. 1). The diffuse boundary is rich in fluid inclusions and some solid inclusions, seemingly calcite is dominant (Fig. 1). The sharp boundary within the purple fluorite (Fig. 1) is coated along the boundary with a thin layer of quartz. The cloudy patches are areas rich in fluid and solid inclusions. Chemically, the fluorite is clean (Figs. 3, 5, 7), trace elements are more abundant in the white/colorless portion than in the purple part (300 ppm versus 120 ppm yttrium). No evidence of pronounced chemical zoning within each color is lacking (Figs. 2,4,6). A scaled spectrum is shown in Fig. 7. There is also a slightly higher titanium content in the white and cloudy portions (up to 1500 ppm versus 300-500 ppm in the purple and colorless portions. The white to colorless portion is evidently later in growth than the purple part and it appears to have grown rapidly. Evidence of elongated crystals emanating in comb texture from the purple portion indicate rapid growth. Boundaries between the crystal grains are often outlined by inclusions and microfractures. The observed heterogeneities attest to rapid growth and competition between crystals during formation, resulting in many inclusions and growth interferences. Date: May 21.2020 Signature




