Chemical compositions of W-rich Nb, Ta-oxide minerals from Hirukawa, Nakatsugawa, Gifu Prefecture, Japan

Yasuyuki Banno

Presentation information

Oral presentation

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

Sun. Sep 18, 2022 9:00 AM - 12:15 PM B251 (Adv. Edu. Res. Bldg. B-2F)

Chairperson:Masanori Kurosawa(Univ. Tsukuba), Ysuyuki Banno(AIST), Koichi Momma(Natl. Museum of Nature and Science)

11:30 AM - 11:45 AM

[R1-10] Chemical compositions of W-rich Nb, Ta-oxide minerals from Hirukawa, Nakatsugawa, Gifu Prefecture, Japan

*Yasuyuki Banno¹ (1. AIST)

Keywords:ferberite, columbite, ixiolite, “wolframoixiolite”, Hirukawa

Microprobe analyses were carried out on W-rich Nb, Ta-oxide minerals in a granite pegmatite from Hirukawa, Nakatsugawa, Gifu Prefecture, Japan. Backscattered electron images indicate that the grain is composed of a W-richer core and a W-poorer mantle. The chemical formulae of averaged compositions of the core and mantle are Fe²⁺_0.440Mn_0.313Fe³⁺_0.171Sc_0.048Zr_0.024Sn_0.007Ti_0.004Nb_0.240Ta_0.021W_0.732O₄, and Mn_0.395Fe²⁺_0.310Fe³⁺_0.069Sc_0.023Ti_0.012Zr_0.006Sn_0.005Nb_0.776Ta_0.078W_0.325O₄, respectively.