Kamarizaite,Fe<Stack><Subscript>3</Subscript><Superscript>3+</Superscript></Stack>(AsO<Subscript>4</Subscript>)<Subscript>2</Subscript>(OH)<Subscript>3</Subscript> · 3H<Subscript>2</Subscript>O,a new mineral species,arsenate analogue of tinticite

Kamarizaite, a new mineral species, has been identified in the dump of the Kamariza Mine, Lavrion mining district, Attica Region, Greece, in association with goethite, scorodite, and jarosite. It was named after type locality. Kamarizaite occurs as fine-grained monomineralic aggregates (up to 3 cm across) composed of platy crystals up to 1 μm in size and submicron kidney-shaped segregations. The new mineral is yellow to beige, with light yellow streak. The Mohs hardness is about 3. No cleavage is observed. The density measured by hydrostatic weighing is 3.16(1) g/cm³, and the calculated density is 3.12 g/cm³. The wavenumbers of absorption bands in the IR spectrum of kamarizaite are (cm^?1; s is strong band, w is weak band): 3552, 3315s, 3115, 1650w, 1620w, 1089, 911s, 888s, 870, 835s, 808s, 614w, 540, 500, 478, 429. According to TG and IR data, complete dehydration and dehydroxylation in vacuum (with a weight loss of 15.3(1)%) occurs in the temperature range 110–420°C. Mössbauer data indicate that all iron in kamarizaite is octahedrally coordinated Fe³⁺. Kamarizaite is optically biaxial, positive: n _min = 1.825, n _max = 1.835, n _mean = 1.83(1) (for a fine-grained aggregate). The chemical composition of kamarizaite (electron microprobe, average of four point analyses) is as follows, wt %: 0.35 CaO, 41.78 Fe₂O₃, 39.89 As₂O₅, 1.49 SO₃, 15.3 H₂O (from TG data); the total is 98.81. The empirical formula calculated on the basis of (AsO₄,SO₄)₂ is Ca_0.03Fe _2.86 ³⁺ (AsO₄)_1.90(SO₄)_0.10(OH)_2.74 · 3.27H₂O. The idealized formula is Fe ₃ ³⁺ (AsO₄)₂(OH)₃ · 3H₂O. Kamarizaite is an arsenate analogue of orthorhombic tinticite, space group Pccm, Pcc2, Pcmm, Pcm2₁, or Pc2m; a = 21.32(1), b = 13.666(6), c =15.80(1) Å, V= 4603.29(5) ų, Z= 16. The strongest reflections of the X-ray powder diffraction pattern [\(\bar d\), Å (I, %) (hkl)] are: 6.61 (37) (112, 120), 5.85 (52) (311), 3.947 (100) (004, 032, 511), 3.396 (37) (133, 431), 3.332 (60) (314), 3.085 (58) (621, 414, 324). The type material of kamarizaite is deposited in the Mineralogical Collection of Technische Universität Bergakademie Freiberg, Germany, inventory number 82199.     

Finding of Re Sulfides in Copper-Sulfide Ores of the Maike Occurrence,Ulytau, Central Kazakhstan

Geology of Ore Deposits - Microinclusions of Re-, Mo-, Cu-, Pb-, and Bi-bearing sulfides are found for the first time in Cu sulfide ores of the Maike occurrence, northern Ulytau. The...     

First Results of U–Th–Pb (SIMS) Geochronological Study of Zircon from Serpentinized Ultramafic Rocks of the Tekturmas Ophiolite Zone (Central Kazakhstan)

Doklady Earth Sciences - Accessory zircon extracted from serpentinized dunite and harzburgite of the Tekturmas Zone of Central Kazakhstan, which is one of the largest ophiolite zones in the western...     

Karchevskyite, [Mg18Al9(OH)54][Sr2(CO3,PO4)9(H2O,H3O)11], a new mineral species of the layered double hydroxide family

Karchevskyite, a new mineral related to the family of layered double hydroxides (LDHs), has been found in the Iron open pit at the Kovdor carbonatite massif, Kola Peninsula, Russia. The mineral occurs as spherulites of up to 1.5 mm in diameter composed of thin, curved lamellae. Dolomite, magnetite, quintinite-3T, strontium carbonate, and fluorapatite are associated minerals. Karchevskyite is white in aggregates and colorless in separate platelets. Its luster is vitreous with a pearly shine on the cleavage surface. The new mineral is nonfluorescent. The Mohs hardness is 2. The cleavage is eminent (micalike), parallel to {001}. The measured density is 2.21(2) g/cm³, and the calculated value is 2.18(1) g/cm³. Karchevskyite is colorless and nonpleochroic in immersion liquids. It is uniaxial, negative, ω = 1.542(2), and ? = 1.534(2). The chemical composition (electron microprobe, average of ten point analyses, standard deviation in parentheses, wt %) is as follows: 29.7(1.1) MgO, 18.3(0.7) Al₂O₃, 7.4(0.4) SrO, 0.2(0.1) CaO, 1.3(0.2) P₂O₅, 14.5(0.4) CO₂, and 28.6 H₂O (estimated by difference); the total is 100. The empirical formula calculated on the basis of nine Al atoms is Mg_18.00Al_9.00(OH)_54.00(Sr_1.79Mg_0.48Ca_0.09)_2.36 (Ca₃)_8.26(PO₄)_0.46(H₂O)_6.54(H₃O)_4.18. The idealized formula is [Mg₁₈Al₉(OH)₅₄][Sr₂(CO₃, PO₄)₉(H₂O, H₃O)₁₁]. The new mineral slowly dissolves in 10% HCl with weak effervescence. Karchevskyite is trigonal; possible space groups are P3, P3, P $ \overline 3 Karchevskyite, a new mineral related to the family of layered double hydroxides (LDHs), has been found in the Iron open pit at the Kovdor carbonatite massif, Kola Peninsula, Russia. The mineral occurs as spherulites of up to 1.5 mm in diameter composed of thin, curved lamellae. Dolomite, magnetite, quintinite-3T, strontium carbonate, and fluorapatite are associated minerals. Karchevskyite is white in aggregates and colorless in separate platelets. Its luster is vitreous with a pearly shine on the cleavage surface. The new mineral is nonfluorescent. The Mohs hardness is 2. The cleavage is eminent (micalike), parallel to {001}. The measured density is 2.21(2) g/cm³, and the calculated value is 2.18(1) g/cm³. Karchevskyite is colorless and nonpleochroic in immersion liquids. It is uniaxial, negative, ω = 1.542(2), and ɛ = 1.534(2). The chemical composition (electron microprobe, average of ten point analyses, standard deviation in parentheses, wt %) is as follows: 29.7(1.1) MgO, 18.3(0.7) Al₂O₃, 7.4(0.4) SrO, 0.2(0.1) CaO, 1.3(0.2) P₂O₅, 14.5(0.4) CO₂, and 28.6 H₂O (estimated by difference); the total is 100. The empirical formula calculated on the basis of nine Al atoms is Mg_18.00Al_9.00(OH)_54.00(Sr_1.79Mg_0.48Ca_0.09)_2.36 (Ca₃)_8.26(PO₄)_0.46(H₂O)_6.54(H₃O)_4.18. The idealized formula is [Mg₁₈Al₉(OH)₅₄][Sr₂(CO₃, PO₄)₉(H₂O, H₃O)₁₁]. The new mineral slowly dissolves in 10% HCl with weak effervescence. Karchevskyite is trigonal; possible space groups are P3, P3, P 1m, P31m, P312, P312, P3m1, or P3m1; unit-cell dimensions are a = 16.055(6), c = 25.66(1) ?, V = 5728(7) ?³, Z = 3. The strongest reflections in the X-ray powder diffraction pattern [d, (I, %)(hkl)] are: 8.52(10)(003), 6.41(4)(004), 5.13(3)(005), 4.27(6)(006), 3.665(9)(007), 3.547(9)(107), 3.081(6)(315). Wavenumbers of absorption bands in the infrared spectrum of the new mineral are (cm⁻¹; s is shoulder): 3470, 3420s, 3035, 2960s, 1650, 1426, 1366, 1024, 937, 860, 779, 678, 615s, 553, 449, 386. Results of thermogravimetric analysis: total weight loss is 42.0 wt %, with three stages of loss: 12.2%, maximum rate at 230°C; 6.1%, maximum rate at 320°C; and 23.7%, maximum rate at 440°C. Karchevskyite is a late-stage hydrothermal mineral. The mineral is named in memory of Russian mineralogist Pavel Karchevsky (1976–2002), who made a significant contribution to the study of carbonatites. The type material of karchevskyite is deposited at the Mineralogical Museum, Division of Mineralogy, St. Petersburg State University, and the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow. Original Russian Text ? S.N. Britvin, N.V. Chukanov, G.K. Bekenova, M.A. Yagovkina, A.V. Antonov, A.N. Bogdanova, N.I. Krasnova, 2007, published in Zapiski Rossiiskogo Mineralogicheskogo Obshchestva, 2007, No. 5, pp. 44–56. The new mineral karchevskyite and its name accepted by the Commission on New Minerals and Mineral Names, Russian Mineralogical Society, March 21, 2005. Approved by the Commission on New Minerals and Mineral Names, International Mineralogical Association, June 30, 2005.