Photomicrograph of dutrowite in plane-polarized light. Symbols after Warr (2021): Ap – “apatite”; Bt – “biotite”; Dtw – dutrowite; Kfs – K-feldspar; Odrv – oxy-dravite; Qz – quartz. “Biotite” is partially altered in “chlorite” and rutile, whereas K-feldspar is sericitized. Red box corresponds to the area where the grain used for single-crystal X-ray diffraction was extracted. Type material. Catalogue number 19890, Museo di Storia Naturale, Università di Pisa. The image is published in an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( http://creativecommons.org/licenses/by/4.0/ ). — Photo: Cristian Biagioni, Ferdinando Bosi, Daniela Mauro, Henrik Skogby, Andrea Dini, and Federica Zaccarini · CC BY 4.0
Dutrowite
Dutrowite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na(Fe²⁺₂.₅Ti₀.₅)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃O.
It crystallizes in the hexagonal crystal system (space group R3m). It is a member of the Tourmaline structural group.
IMA symbol Dtw, IMA status: approved, named in 2020.
It is found associated with Distribution From the Fornovolasco metarhyolite formation, close to the Boscaccio locality, Fornovolasco, Fabbriche di Vergemoli (LU), Apuan Alps, Tuscany.