Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Résumé Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Yakovenchuk, V. N. Articles by Zalkind, O. A. Search for Related Content GeoRef GeoRef Citation

KRIVOVICHEVITE, Pb₃[Al(OH)₆](SO₄)(OH), A NEW MINERAL SPECIES FROM THE LOVOZERO ALKALINE MASSIF, KOLA PENINSULA, RUSSIA

Victor N. Yakovenchuk^1,, Yakov A. Pakhomovsky¹, Yuri P. Men’shikov¹, Julia A. Mikhailova¹, Gregory Yu. Ivanyuk¹ and Oleg A. Zalkind²

¹ Geological Institute, Kola Science Center, Russian Academy of Sciences, 14 Fersman Street, Apatity 184209, Russia
² Institute of Chemistry, Technology of Rare Elements and Mineral Resources, Kola Science Center, Russian Academy of Sciences, 14 Fersman Street, Apatity 184209, Russia

E-mail address: yakovenchuk{at}geoksc.apatity.ru

Krivovichevite, Pb₃[Al(OH)₆](SO₄)(OH), is a new sulfate found in a natrolite – aegirine – orthoclase vein within lujavrite at Mt. Lepkhe–Nelm, Lovozero alkaline massif, Kola Peninsula, Russia. It occurs as large (up to 1 cm diameter) equant grains within galena aggregates in natrolite, in intimate association with anglesite, cerussite, hydrocerussite, leadhillite and lanarkite. It is a late hydrothermal mineral produced by alteration of galena. Other associated minerals are anatase, arsenopyrite, fluorapatite, fluorite, halloysite, heulandite-Ca, heulandite-Sr, kupletskite, lamprophyllite, leucophanite, magnesio-arfvedsonite, mangan-neptunite, microcline, monazite-(La), polylithionite, quartz, opal, rhabdophane-(Ce) and titanite. The mineral is transparent and colorless, with a vitreous luster and a white streak. A cleavage was not observed, and the fracture is conchoidal. The Mohs hardness is about 3. The mineral is brittle. Krivovichevite is uniaxial (–): n(meas) 1.9 (589 nm), n(calc.) = 1.85. It is nonpleochroic. The mean chemical composition, determined with an electron microprobe is: PbO 76.49, CaO 0.02, Al₂O₃ 5.38, SO₃ 9.27, H₂O (Penfield method) 7.20, total 98.36 wt.%. The empirical formula, calculated on the basis of Pb + Ca + Al + S = 5 apfu is Pb_3.04 Al_0.94(S_1.03O_3.98)(OH)_7.08. An ideal formula taking into account the single-crystal study of its structure is: Pb₃[Al(OH)₆](SO₄) (OH). Krivovichevite is trigonal, R3c, a 7.693(8), c 31.57(9) Å, V 1618(6) ų, Z = 6. The strongest six X-ray powder-diffraction lines [d in Å(I)(hkl)] are: 3.58(100)(201), 3.10(60)(116), 2.591(90)(119), 2.216(50)(030), 2.048(70)(036), 1.704(80)(317). The structure of krivovichevite has been refined to R₁ = 0.034 for 681 reflections. It contains isolated Al(OH)₆^3– octahedra and SO₄^2– tetrahedra, Pb²⁺ cations and OH^– anions. The infrared spectrum indicates the presence of structural (OH)^– and sulfate absorption bands. The mineral is named in honor of Sergey Vladimirovich Krivovichev, Russian mineralogist and crystallographer, Professor at St. Petersburg State University. Krivovichevite belongs to a new structure-type of minerals and inorganic compounds. Chemically related to krivovichevite are minerals of the beudantite and alunite groups.

Keywords: krivovichevite, new mineral species, sulfate, Lovozero alkaline massif, Kola Peninsula, Russia.