Vibrational spectroscopic characterization of the phosphate mineral kulanite Ba(Fe(2+),Mn(2+),Mg)2(Al,Fe(3+))2(PO4)3(OH)3.
The mineral kulanite BaFe2Al2(PO4)3(OH)3, a barium iron aluminum phosphate, has been studied by using a combination of electron microscopy and vibrational spectroscopy. Scanning electron microscopy with EDX shows the mineral is homogenous with no other phases present. The Raman spectrum is dominated by an intense band at 1022cm(-1) assigned to the PO4(3-)ν1 symmetric stretching mode. Low intensity Raman bands at 1076, 1110, 1146, 1182cm(-1) are attributed to the PO4(3-)ν3 antisymmetric stretching vibrations. The infrared spectrum shows a complex spectral profile with overlapping bands. Multiple phosphate bending vibrations supports the concept of a reduction in symmetry of the phosphate anion. Raman spectrum at 3211, 3513 and 3533cm(-1) are assigned to the stretching vibrations of the OH units. Vibrational spectroscopy enables aspects on the molecular structure of kulanite to be assessed.
Johntomaite, a new member of the bjarebyite group of barium phosphates: description and structure refinement
Summary Johntomaite, ideally BaFe2+2Fe3+2(PO4)3(OH)3, is the Fe2+-analogue of perloffite and represents a new member of the bjarebyite group of barium phosphates. It occurs as an extremely rare mineral on the dumps of the Spring Creek copper mine near Wilmington in the southern Flinders Ranges of South Australia, where it forms clusters of greenish black, monoclinic prisms 0.3 to 1 mm in length. It is associated with quartz, libethenite, pseudomalachite and mitridatite. It is opaque with a dark greyish green streak, it has a vitreous, greasy to subadamantine lustre, a perfect cleavage parallel to {100}, an irregular fracture, a Mohs hardness of 4½, and D(meas.) 4.05(1), D(calc.) 4.084 g/cm3. Optically, it is biaxial negative, with α 1.817(3), β 1.829(6), γ 1.837(3), 2Vα ∼ 80–85(5)° (meas.), 78.0° (calc.). Pleochroism is strong: X bluish green, Y dark brownish green, Z brownish; absorption Y > X ≥ Z; orientation Z = b. Dispersion is strong, (probably) r ≪ v. The mineral is monoclinic, P21/m, with a 9.199(9), b 12.359(8), c5.004(2) Aring;, β 100.19(6)°, V 559.9(5) Aring;3 and Z = 2. The strongest lines in the X-ray powder diffraction pattern are [d(I ) hkl]: 3.159 (100) 031,−221; 2.983 (50) 211; 2.749 (50b) 221,−311; 4.573 (40) 011; 3.091 (40) −131. Electron microprobe analysis yielded (wt.%): BaO 21.96, FeO 13.34, CaO 3.28, MnO 2.67, Na2O 0.07, MgO 0.05, CuO 0.07, ZnO 0.06, Fe2O3 22.62, Al2O3 0.25, P2O5 30.45, SiO2 0.13, F 0.36, H2O 3.73 (calc.), less O ≡ F − 0.15, sum 98.89. The empirical formula is Ba1.00 (Fe2+1.29Ca0.41Mn0.26Na0.02Mg0.01Cu0.01Zn0.01)Σ2.01(Fe3+1.97Al0.03)Σ2.00 [(P2.98Si0.02) O4]3.00(OH2.85F0.13)Σ2.98, based on three (P + Si) and the assumption that the Fe(2) site is completely filled with Fe3+ and Al. A single-crystal structure refinement (R = 4.92%) confirmed the bjarebyite-type structure of johntomaite. Both refinement and chemical analyses demonstrate that Ca and (Fe + Mn) are negatively correlated. Johntomaite is named after Mr. John Toma, amateur mineralogist and finder of the mineral. The type specimen is deposited at the South Australian Museum, Adelaide, Australia.ZusammenfassungJohntomait, ein neues Glied der Bjarebyit-Gruppe von Bariumphosphaten: Beschreibung und Strukturverfeinerung
 Johntomait, BaFe2+2Fe3+2(PO4)3(OH)3, ist ein neues Glied der Bjarebyit-Gruppe von Bariumphosphaten, und stellt das Fe2+-Analogon von Perloffit dar. Es kommt extrem selten in Haldenmaterial der Spring Creek-Kupfermine bei Wilmington, südliche Flinders Ranges, Südaustralien, vor. Johntomait bildet Aggregate von grünlich schwarzen, monoklinen Prismen mit einer Länge von 0.3 bis 1 mm, und ist vergesellschaftet mit Quarz, Libethenit, Pseudomalachit und Mitridatit. Das Mineral ist undurchsichtig, mit dunkelgraugrünem Strich, glasigem, harzigem bis diamantartigem Glanz, perfekter Spaltbarkeit parallel {100}, unregelmäßigem Bruch, Mohs-Härte 4½, und D(gem.) 4.05(1), D(ber.) 4.084 g/cm3. Optische Eigenschaften: zweiachsig negativ, α 1.817(3), β 1.829(6), γ 1.837(3), 2Vα ∼ 80–85(5)° (gem.), 78.0° (ber.). Der Pleochroismus ist ausgeprägt: X bläulich grün, Y dunkelbräunlich grün, Z bräunlich; Absorption Y > X ≥ Z; Z = b; (wahrscheinlich) r ≪ v. Das Mineral ist monoklin, P21/m, a 9.199(9), b 12.359(8), c 5.004(2) Aring;, β 100.19(6)°, V  559.9(5) Aring;3, Z = 2. Stärkste Linien im Röntgenpulverdiagramm [d (I ) hkl]: 3.159 (100) 031,−221; 2.983 (50) 211; 2.749 (50b) 221,−311; 4.573 (40) 011; 3.091 (40) −131. Elektronenmikrosondenanalysen ergaben (Gew.%): BaO 21.96, FeO 13.34, CaO 3.28, MnO 2.67, Na2O 0.07, MgO 0.05, CuO 0.07, ZnO 0.06, Fe2O3 22.62, Al2O3 0.25, P2O5 30.45, SiO2 0.13, F 0.36, H2O 3.73 (ber.), minus O ≡ F −0.15, Summe 98.89. Die empirische Formel ist Ba1.00(Fe2+1.29Ca0.41Mn0.26Na0.02Mg0.01Cu0.01Zn0.01)Σ2.01 (Fe3+1.97Al0.03)Σ2.00 [(P2.98Si0.02)O4]3.00(OH2.85F0.13)Σ2.98, basierend auf drei (P + Si) und der Annahme, daß die Fe(2)-Position vollständig mit Fe3+ und Al besetzt ist. Eine Verfeinerung von Einkristallbeugungsdaten (R = 4.92%) bestätigte den Bjarebyit-Typ der Struktur von Johntomait. Sowohl Verfeinerung als auch chemische Analysen zeigen eine negative Korrelation zwischen Ca und (Fe + Mn). Johntomait ist benannt nach John Toma, Amateurmineraloge und Finder des Minerals. Das Typmaterial befindet sich im South Australian Museum, Adelaide, Australien.
Inhibition of sterol and fatty acid biosyntheses by cerulenin in cell-free systems of yeast.
amide6>7). Cerulenin was found to cause a curling of the mycelium of filamentous fungi such as Trichophyton and Microsporiurns~1Q). The action mechanism of cerulenin has been investigated with Candida stellatoidea (C. stellatoidea) and Saccharomyces cerevisiae (S. cerevisiae)ll). In the previous experiments using the whole cells of C. stellatoidea, it has been observed to inhibit neither the biosyntheses of nucleic acids, protein, and cell wall, nor the exogenous