Guérinite Ca₆(HAsO₄)₃(AsO₄)₂∙10.5H₂O – a revision of the mineral formula

Author(s)

Irene Liebhart, Branko Rieck, Gerald Giester

Abstract

A single crystal of guérinite from the Plaka Mine, Lavrion, Greece, was examined by X-ray diffraction. The mineral crystallizes in the monoclinic space group P2₁/n with unit cell parameters a = 17.628 (2), b = 6.728 (1), c = 23.384 (3) Å, β = 90.68 (1)°, V = 2773.4 (6) ų. The originally reported mineral formula Ca₅(HAsO₄)₂(AsO₄)₂∙9H₂O, Z = 5 should be revised to Ca₆(HAsO₄)₃(AsO₄)₂∙10.5H₂O, Z = 4. Accordingly, guérinite is no longer considered a polymorph to ferrarisite. The structure is characterized by complex layers consisting of corner- and edge sharing of CaOn (_n = 7, 8) polyhedra and
arsenate groups. The connection between these units is achieved exclusively via hydrogen bonding.

Organisation(s)

Department of Mineralogy and Crystallography

Journal

Mineralogy and Petrology

Volume

118

Pages

547-554

No. of pages

8

ISSN

0930-0708

DOI

https://doi.org/10.1007/s00710-024-00873-2

Publication date

10-2024

Peer reviewed

Yes

Austrian Fields of Science 2012

105116 Mineralogy, 105113 Crystallography

Keywords

ASJC Scopus subject areas

Geochemistry and Petrology, Geophysics

Portal url

https://ucrisportal.univie.ac.at/en/publications/a3103ca0-51a4-477e-ba82-f6413e7ff9f3