SPECTROSCOPIC CHARACTERIZATION OF FLUORITE: RELATIONSHIPS BETWEEN TRACE ELEMENT ZONING, DEFECTS AND COLOR
Abstract (Summary)This thesis consists of two separate papers on color in fluorite. In the first paper, synthetic fluorites doped with various REEs (10-300 ppm) were analyzed using direct current plasma spectrometry, optical absorption spectroscopy, fluorescence spectrophotometry, and electron paramagnetic resonance spectroscopy before and after receiving 10-25 Mrad of 60Co gamma irradiation. The combined results of these techniques indicate that the irradiation-induced color of the Y-, Gd-, La- and Ce-doped samples are the result of a REE-associated fluorine vacancy that traps two electrons. Divalent samarium may be the cause of the irradiation-induced green color of the Sm-doped sample. In the second paper, fluorite crystals from Bingham, NM, Long Lake, NY, and Westmoreland, NH were similarly investigated to determine the relationship between sectorally zoned trace elements, defects, and color. The results indicate causes of color similar to those in the synthetic samples with the addition of simple F-centers.
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:color fluorite defects
Date of Publication:01/01/2003