R2: Crystal structure, crystal chemistry, physical properties of minerals, crystal growth and applied mineralogy

[R2-15] Thermally treatment on metamict minerals: case of fergusonite

*Makoto Tokuda¹, Akira Yoshiasa², Seiichiro Uehara³, Ritsuro Miyawaki⁴, Koichi Momma⁴, Kazumasa Sugiyama¹ (1. Tohoku Uni. IMR, 2. Kumamoto Univ., Sci., 3. Kyusyu Univ., Sci., 4. Nat'l. Mus. Nat. Sci.)

Keywords:Metamict, Fergusonite-(Y), Single-crystal X-ray diffraction

We report the problem of a thermally treatment on metamict minerals in the case of fergusonite. We used a mild metamict fergusonite from Okue, Miyazaki Prefecture, Japan. We concluded a thermally untreated fergusonite is monoclinic which is difficult to discriminate from T phase fergusonite. Obviously, the diffraction pattern of the annealed fergusonite is different from that of un-annealed fergusonite. We concluded that the information about metamictization in fergusonite is disappeared by thermally treatment.