Thermal Expansion of Fedotovite K2Cu3O(SO4)3 and Piypite K4Cu4O(SO4)4·(Na,Cu)Cl

A. P. Shablinskiia, b, *, S. K. Filatovc, Y. P. Biryukova, A. A. Yurieva, c, and L. P. Vergasovad

a Grebenshchikov Institute of Silicate Chemistry, Russian Academy of Sciences, St. Petersburg, 199034 Russia

b St. Petersburg State Electrotechnical University “LETI,” St. Petersburg, 197022 Russia

c Institute of Earth Sciences, St. Petersburg State University, St. Petersburg, 199034 Russia

d Institute of Volcanology and Seismology, Far East Branch, Russian Academy of Sciences, Petropavlovsk-Kamchatsky, 683006 Russia

Correspondence to: *e-mail: shablinskii.andrey@mail.ru

Received 28 March, 2023

Abstract—This paper presents the results of a study of the thermal behavior of fedotovite K2Cu3O(SO4)3 and piypite K4Cu4O(SO4)4∙(Na,Cu)Cl minerals in a wide temperature range. The crystal structure of the holotype piypite specimen is refined at room temperature. The mechanisms of thermal expansion of minerals depending on the crystal structure are described.

Keywords: sulfates, piypite, fedotovite, thermal expansion, crystal structure

DOI: 10.1134/S1087659623600333