Skip to Main Content
GEOREF RECORD

Saranchinaite, Na (sub 2) Cu(SO (sub 4) ) (sub 2) , a new exhalative mineral from Tolbachik Volcano, Kamchatka, Russia, and a product of the reversible dehydration of krohnkite, Na (sub 2) Cu(SO (sub 4) ) (sub 2) (H (sub 2) O) (sub 2)

Oleg I. Siidra, Evgeniya A. Lukina, Evgeniy V. Nazarchuk, Wulf Depmeier, Rimma S. Bubnova, Atali A. Agakhanov, Evgeniya Yu. Avdontseva, Stanislav K. Filatov and Vadim M. Kovrugin
Saranchinaite, Na (sub 2) Cu(SO (sub 4) ) (sub 2) , a new exhalative mineral from Tolbachik Volcano, Kamchatka, Russia, and a product of the reversible dehydration of krohnkite, Na (sub 2) Cu(SO (sub 4) ) (sub 2) (H (sub 2) O) (sub 2)
Mineralogical Magazine (April 2018) 82 (2): 257-274

Abstract

The new mineral saranchinaite, ideally Na (sub 2) Cu(SO (sub 4) ) (sub 2) , was found in sublimates of the Saranchinaitovaya fumarole, Naboko Scoria Cone, Tolbachik volcano, Kamchatka, Russia. Its discovery and study has enabled the characterization of the thermal decomposition of krohnkite and provided an insight into the high-temperature behaviour of other krohnkite-type materials. Saranchinaite is monoclinic, P21, a = 9.0109(5), b = 15.6355(8), c = 10.1507(5) Aa, beta = 107.079(2) degrees , V = 1367.06(12) Aa (super 3) , Z = 8 and R1 = 0.03. Saranchinaite is a unique mineral in that two of its four independent Cu sites display a very unusual Cu (super 2+) coordination environment with two weak Cu-O bonds of approximately 2.9-3.0 Aa, resulting in [4+1+2] CuO (sub 7) polyhedra. Each of the Cu-centred polyhedra shares common corners with SO (sub 4) tetrahedra resulting in a [Cu (sub 4) (SO (sub 4) ) (sub 8) ] (super 8-) framework with a complex channel system occupied by Na atoms. Saranchinaite is sensitive to moisture and transforms into krohnkite within one week when exposed to open air at 87% relative humidity and 25 degrees C. High-temperature X-ray diffraction studies were performed for both krohnkite (from La Vendida mine, Antofagasta Region, Chile) and saranchinaite. During thermal expansion krohnkite retains its strongly anisotropic character up to its full dehydration and the formation of saranchinaite at approximately 200 degrees C, which then transforms back into krohnkite after exposure to open air. The thermal expansion of saranchinaite is more complex than that of krohnkite. Saranchinaite is stable up to 475 degrees C with subsequent decomposition into tenorite CuO, thenardite Na (sub 2) SO (sub 4) and unidentified phases.


ISSN: 0026-461X
EISSN: 1471-8022
Coden: MNLMBB
Serial Title: Mineralogical Magazine
Serial Volume: 82
Serial Issue: 2
Title: Saranchinaite, Na (sub 2) Cu(SO (sub 4) ) (sub 2) , a new exhalative mineral from Tolbachik Volcano, Kamchatka, Russia, and a product of the reversible dehydration of krohnkite, Na (sub 2) Cu(SO (sub 4) ) (sub 2) (H (sub 2) O) (sub 2)
Affiliation: St. Petersburg State University, Department of Crystallography, Russian Federation
Pages: 257-274
Published: 201804
Text Language: English
Publisher: Mineralogical Society, London, United Kingdom
References: 57
Accession Number: 2018-081715
Categories: Mineralogy of non-silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 8 tables
N55°49'02" - N55°49'02", E160°22'02" - E160°22'02"
Secondary Affiliation: Russian Academy of Sciences, Kola Science Center, RUS, Russian FederationUniversitaet Kiel, DEU, GermanyFersman Mineralogical Museum, RUS, Russian Federation
Country of Publication: United Kingdom
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute. Abstract, Copyright, Mineralogical Society of Great Britain and Ireland. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 2018
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal