Microphotograph (a) and back-scattered electron (BSE) image (b) of ferro-ferri-holmquistite. Red square shown in (a) corresponds to area of BSE image (b). Abbreviations: Bt = biotite (strongly altered), Pl = plagioclase and Qz = quartz. The image is published in an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( https://creativecommons.org/licenses/by/4.0/ ). — Photo: Mariko Nagashima, Teruyoshi Imaoka, Takashi Kano, Jun-ichi Kimura, Qing Chang and Takashi Matsumoto · CC BY 4.0
Ferro-ferri-holmquistite
Ferro-ferri-holmquistite is an IMA-recognized mineral species in the silicate class, with the chemical formula Li₂(Fe²⁺₃Fe³⁺₂)(Si₈O₂₂)(OH)₂.
It crystallizes in the orthorhombic crystal system (space group Pnma). It is a member of the Amphibole structural group.
IMA symbol Ffhlm, IMA status: approved, named in 2022.