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Cupromolybdite, Cu (sub 3) O(MoO (sub 4) ) (sub 2) , a new fumarolic mineral from the Tolbachik Volcano, Kamchatka Peninsula, Russia

Michael E. Zelenski, Natalia V. Zubkova, Igor V. Pekov, Yuri S. Polekhovsky and Dmitry Yu. Pushcharovsky
Cupromolybdite, Cu (sub 3) O(MoO (sub 4) ) (sub 2) , a new fumarolic mineral from the Tolbachik Volcano, Kamchatka Peninsula, Russia
European Journal of Mineralogy (August 2012) 24 (4): 749-757


Cupromolybdite is a new fumarolic mineral from the New Tolbachik scoria cones of Tolbachik volcano, Kamchatka Peninsula, Russia. Cupromolybdite forms prismatic crystals up to 150 mu m in length or acicular crystals with a thickness and length of 1-5 mu m and 100 mu m, respectively. The acicular crystals of cupromolybdite are typically combined in radiating aggregates. The mineral is associated with piypite, fedotovite, vergasovaite, hematite, magnetite, aphthitalite, langbeinite, palmierite, As-bearing orthoclase, lammerite, klyuchevskite, alumoklyuchevskite, euchlorine, lyonsite, pseudolyonsite, averievite, rutile and native gold. Cupromolybdite is honey-yellow or brown, and its acicular crystals are bright yellow. The mineral has yellow or light brown streak and an adamantine lustre. Cupromolybdite is brittle, and its fracture ranges from uneven to splintery. The calculated density is 4.512 g/cm (super 3) . The reflectance values (R (sub 1) and R (sub 2) , %) in air for the four COM wavelengths are 14.95, 16.3 (470 nm), 13.4, 14.85 (546 nm), 12.73, 14.16 (589 nm), and 12.15, 13.5 (650 nm). The chemical composition (the mean of 7 electron microprobe analyses) of cupromolybdite is: CuO 43.03, FeO 0.08, ZnO 0.53, MoO (sub 3) 54.48, SO (sub 3) 0.71, V (sub 2) O (sub 5) 0.28, SiO (sub 2) 0.04, total 99.15 wt%, corresponding, on the basis of 9 O atoms, to (Cu (sub 2.83) Zn (sub 0.03) Fe (sub 0.01) ) (sub Sigma 2.87) (Mo (sub 1.98) S (sub 0.05) V (sub 0.02) ) (sub Sigma 2.05) O (sub 9) . The simplified formula of cupromolybdite is Cu (sub 3) O(MoO (sub 4) ) (sub 2) =Cu (sub 3) Mo (sub 2) O (sub 9) . Cupromolybdite is orthorhombic, space group Pnma, a=7.6638(1), b=6.8670(1), c=14.5554(2) Aa, V=766.01(2) Aa (super 3) and Z=4. The strongest powder-diffraction lines [d in Aa (I) (hkl)] are: 7.312 (67) (002); 3.518 (55) (113); 3.436 (100) (020); 3.301 (99) (210, 104); 3.065 (79) (121); 2.556 (62) (220); 2.506 (66) (301, 024). The crystal structure was solved from single-crystal data and refined to R=0.0314. Cupromolybdite is a natural analogue of the synthetic compound Cu (sub 3) Mo (sub 2) O (sub 9) and the S-free analogue of vergasovaite, Cu (sub 3) O[(Mo,S)O (sub 4) ][SO (sub 4) ]. The crystal structure of cupromolybdite contains strings of corner-shared Cu(1)O (sub 6) octahedra elongated in the [010] direction. In cupromolybdite, the Cu(2)O (sub 5) square pyramids and the Cu(3)O (sub 6) distorted octahedra are linked to the Cu(1)O (sub 6) octahedra of the strings by edges and to the MoO (sub 4) and (Mo,S)O (sub 4) tetrahedra by vertices. A minor admixture of S is concentrated in one of two independent tetrahedral positions. Cupromolybdite is named for its chemical composition.

ISSN: 0935-1221
EISSN: 1617-4011
Serial Title: European Journal of Mineralogy
Serial Volume: 24
Serial Issue: 4
Title: Cupromolybdite, Cu (sub 3) O(MoO (sub 4) ) (sub 2) , a new fumarolic mineral from the Tolbachik Volcano, Kamchatka Peninsula, Russia
Affiliation: Russian Academny of Sciences, Institute of Experimental Mineralogy, Chernogolovka, Russian Federation
Pages: 749-757
Published: 201208
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Germany
References: 20
Accession Number: 2012-073272
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: Moscow State University, RUS, Russian FederationSaint Petersburg State University, RUS, Russian Federation
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, copyright, Schweizerbart'sche Verlagsbuchhandlung. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201238
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