R1: Characterization and description of minerals (Joint Session with The Gemmological Society of Japan)

[R1-08] Cylindrical amesite from Yakiyama, Iizuka, Fukuoka Prefecture, Japan

Yuki Isshiki², Yuya Takeda², *Seiichiro Uehara¹, Satomi Enjyu³ (1. Kyushu Univ. Museum, 2. Kyushu Univ. Fac. Sci., 3. Ehime Univ.)

Keywords:Cylindrical amesite, Al-serpentine, New structure, Yakiyama, serpentine minerals

Al-serpentine is a white opaque mass and isotropic under the polarizing microscope. Amesite is a pale brown transparent crystal. Al-serpentine and amesite were investigated using scanning electron microscope and transmission electron microscope with EDS. Al-serpentine is a mixture nano-size grains of cylindrical, fibrous, and infinite shape. The dimensions of cylindrical grain is outer diameter of 120-350 nm, inner diameter of 80-250 nm and length of 2 µm. Chemical composition cylindrical grain is amesite composition (Al cation number is 1.3 at O=7).