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

12:30 PM - 2:00 PM JST(3:30 AM - 5:00 AM UTC)

[R1P-21] New data on pargasite with Ca at the A site from Ogouchi, Hinokage, Nishiusuki, Miyazaki Prefecture, Japan

*Yasuyuki Banno¹, Toshiro Okada², Seiichiro Uehara³ (1. AIST, 2. Fukuoka Mineral Club, 3. Kyushu Univ.)

Keywords:

Pargasite,Fluoro-cannilloite,solid-solution,Ogouchi Hinokage,Miyazaki Prefecture

Calcium amphibole with Ca at the A site was found from Ogouchi, Hinokage, Miyazaki Prefecture, Japan. The amphibole consists of parts that are Al-rich and Al-poor, respectively. The empirical formulae with all ferrous Fe for averaged compositions of the Al-rich and Al-poor parts, based on 24(O, OH, F, Cl) with (OH, F, Cl) = 2 atoms per formula unit are ^A(Na_0.523K_0.163Ca_0.251Sr_0.054)_Σ0.991^B(Ca_1.912Mn_0.002Fe²⁺_0.086)_Σ2.000^C(Mg_4.232Fe²⁺_0.068Al_0.590Ti_0.104Cr_0.006)_Σ5.000^T(Si_5.901Al_2.099)_Σ8.000O₂₂^W[(OH)_1.201F_0.777Cl_0.022]_Σ2.000 and ^A(Na_0.635K_0.096Ca_0.137Sr_0.037)_Σ0.905^B(Ca_1.918Fe²⁺_0.082)_Σ2.000^C(Mg_4.392Fe²⁺_0.021Al_0.527Ti_0.056Cr_0.004)_Σ5.000^T(Si_6.276Al_1.724)_Σ8.000O₂₂^W[(OH)_1.319F_0.669Cl_0.012]_Σ2.000, respectively, which correspond to F-rich pargasite with (Ca,Sr) at the A site.