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Updated: Jul 12, 2026
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Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples
Published on: June 19, 2018
Ordered lattice defects in colored fluorite: direct observations.
Science (New York, N.Y.)
|January 18, 1974
Summary
Transmission electron microscopy revealed ordered defect aggregates in fluorite crystals. These aggregates, identified as color centers, are the primary cause of fluorite
Area of Science:
- Materials Science
- Solid-State Physics
- Mineralogy
Background:
- Natural fluorite exhibits coloration, the origin of which has been debated.
- Understanding defect structures is crucial for materials characterization.
Purpose of the Study:
- To investigate the microstructural origins of fluorite coloration.
- To confirm the role of color centers in fluorite's optical properties.
Main Methods:
- Transmission electron microscopy (TEM) was employed to examine natural fluorite samples.
- High-energy (200-kilovolt) electron microscopy was used to induce and observe color changes.
Main Results:
- Ordered arrays of defect aggregates were identified within the (111) planes of fluorite.
- Electron microscopy induced intense blue coloration in specific sample areas.
- The observed defects directly correlated with the induced coloration.
Conclusions:
- Color centers, specifically aggregates observed in ordered arrays, are primarily responsible for the coloration of natural fluorite.
- TEM is an effective technique for elucidating the relationship between crystal defects and optical properties in minerals.
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