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N. V. Chukanov I. V. Pekov S. Möckel A. A. Mukhanova D. I. Belakovsky L. A. Levitskaya G. K. Bekenova 《Geology of Ore Deposits》2010,52(7):599-605
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 Ca0.03Fe 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) Å3, 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. 相似文献
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N. V. Chukanov I. V. Pekov E. O. Perepelitsina V. N. Ermolaeva S. A. Vozchikova 《Geology of Ore Deposits》2010,52(8):748-754
In alkaline pegmatites of the Khibiny pluton niobium oxosilicates with (Nb + Ti)/Si ≥ 1 and Nb > Ti occur in intimate fine
intergrowths with endogenic organic matter, which makes it possible to assume a genetic relationship between them. Such intergrowths
from pegmatites of Mounts Kukisvumchorr and Koashva have been studied by electron microscopy, electron microprobe, IR spectroscopy,
and exclusion chromatography. Unsaturated hydrocarbon groups, including aromatic ones, and carboxylate groups are prevalent
in the organic matter intergrown with the niobium oxosilicates. The molecular weight distribution in the part of the bitumen
soluble in tetrahydrofurane is polymodal, probably due to its formation as a result of parallel reactions on several catalytic
centers of polymerization. 相似文献
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