Microstructure and occurrence of lithiophorite from Nagatare pegmatite, Fukuoka Prefecture

Abstract

Lithiophorite from Nagatare pegmatite consists of fine disk-shape crystals with 1 µm in diameter, 500 nm in thickness. The chemical composition and unit cell parameters are (Li_1.00Al_2.00)_Σ3.00(Mn⁴⁺_2.00Mn³⁺_0.86Fe³⁺_0.03Al_0.11)_Σ3.00O₆(OH)₆, and a = 2.921(5), c = 28.44(5) and V = 210.1(7). Alternative MnO₆ octahedral sheet and (Al,Li)(OH)₆ octahedral sheet were observed in STEM-HAADF image. HRTEM image indicates ordered structure in (Al,Li)(OH)₆ octahedral sheet.