69 documents found, page 1 of 7
A vibrational spectroscopic study of the copper bearing silicate mineral ludden...
Frost, Ray Leslie; López, Andrés; Xi, Yunfei; Cipriano, Ricardo Augusto ScholzThe molecular structure of the copper–lead silicate mineral luddenite has been analysed using vibrational spectroscopy. The mineral is only one of many silicate minerals containing copper. The intense Raman band at 978 cm 1 is assigned to the m1 (A1g) symmetric stretching vibration of Si5O14 units. Raman bands at 1122, 1148 and 1160 cm 1 are attributed to the m3 SiO4 antisymmetric stretching vibrations. The ban...
A vibrational spectroscopic study of the anhydrous phosphate mineral sidorenkit...
Frost, Ray Leslie; López, Andrés; Cipriano, Ricardo Augusto Scholz; Belotti, Fernanda Maria; Xi, YunfeiSidorenkite is a very rare low-temperature hydrothermal mineral, formed very late in the crystallization of hyperagpaitic pegmatites in a differentiated alkalic massif (Mt. Alluaiv, Kola Peninsula, Russia). Sidorenkite Na3Mn(PO4)(CO3) is a phosphate–carbonate of sodium and manganese. Such a formula with two oxyanions lends itself to vibrational spectroscopy. The sharp Raman band at 959 cm 1 and 1012 cm 1 are as...
Raman and infrared spectroscopic study of turquoise minerals.
Čejka, Jiři; Sejkora, Jiři; Macek, Ivo; Malíková, Radana; Wang, Lina; Cipriano, Ricardo Augusto Scholz; Xi, Yunfei; Frost, Ray LeslieRaman and infrared spectra of three well-defined turquoise samples, CuAl6(PO4)4(OH)8_4H2O, from Lavender Pit, Bisbee, Cochise county, Arizona; Kouroudaiko mine, Faleme river, Senegal and Lynch Station, Virginia were studied, interpreted and compared. Observed Raman and infrared bands were assigned to the stretching and bending vibrations of phosphate tetrahedra, water molecules and hydroxyl ions. Approximate O–...
A vibrational spectroscopic study of the arsenate mineral bayldonite (Cu,Zn)3Pb...
Frost, Ray Leslie; López, Andrés; Gonçalves, Guilherme de Oliveira; Cipriano, Ricardo Augusto Scholz; Xi, YunfeiWe have studied the vibrational spectra of the mineral bayldonite, a hydroxy arsenate of copper and lead of formula Cu3Pb(AsO3OH)2(OH)2 from the type locality, the Penberthy Croft Mine, St Hilary, Mount’s Bay District, Cornwall, England and relate the spectra to the mineral structure. Raman bands at 896 and 838 cm_1 are assigned to the ðAsO4Þ3_ m1 symmetric stretching mode and the second to the ðAsO4Þ3_ m3 anti...
Vibrational spectroscopic characterization of the phosphate mineral ludlamite (...
Frost, Ray Leslie; Xi, Yunfei; Cipriano, Ricardo Augusto Scholz; Belotti, Fernanda MariaThe objective of this work is to analyze ludlamite (Fe,Mn,Mg)3(PO4)2_4H2O from Boa Vista mine, Galiléia, Brazil and to assess the molecular structure of the mineral. The phosphate mineral ludlamite has been characterized by EMP-WDS, Raman and infrared spectroscopic measurements. The mineral is shown to be a ferrous phosphate with some minor substitution of Mg and Mn. Raman bands at 917 and 950 cm_1 are assigned...
Infrared and Raman spectroscopic characterization of the carbonate mineral huan...
Frost, Ray Leslie; López, Andrés; Cipriano, Ricardo Augusto Scholz; Xi, Yunfei; Belotti, Fernanda MariaRaman spectroscopy complimented with infrared spectroscopy has been used to study the rare earth based mineral huanghoite with possible formula given as BaCe(CO3)2F and compared with the Raman spectra of a series of selected natural halogenated carbonates from different origins including bastnasite, parisite and northupite. The Raman spectrum of huanghoite displays three bands are at 1072, 1084 and 1091 cm^-1 a...
Vibrational spectroscopy of the mineral meyerhofferite CaB3O3(OH)5 H2O - an ass...
Frost, Ray Leslie; López, Andrés; Xi, Yunfei; Cipriano, Ricardo Augusto Scholz; Costa, Geraldo Magela da; Belotti, Fernanda MariaMeyerhofferite is a calcium hydrated borate mineral with ideal formula: CaB3O3(OH)5_H2O and occurs as white complex acicular to crude crystals with length up to _4 cm, in fibrous divergent, radiating aggregates or reticulated and is often found in sedimentary or lake-bed borate deposits. The Raman spectrum of meyerhofferite is dominated by intense sharp band at 880 cm_1 assigned to the symmetric stretching mode...
Vibrational spectroscopic characterization of the phosphate mineral kulanite Ba...
Frost, Ray Leslie; López, Andrés; Xi, Yunfei; Granja, Amanda; Cipriano, Ricardo Augusto ScholzThe 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 1022 cm_1 assigned to the PO3_ 4 m1 symmetric stretching mode. Low intensity Raman bands at...
Vibrational spectroscopy of the borate mineral chambersite MnB7O13Cl - implicat...
Frost, Ray Leslie; López, Andrés; Cipriano, Ricardo Augusto Scholz; Xi, YunfeiChambersite is a manganese borate mineral with formula: MnB7O13Cl and occurs as colorless crystals in the monoclinic pyramidal crystal system. Raman bands at 902, 920, 942 and 963 cm^-1 are assigned to the BO stretching vibration of the B7O13 units. Raman bands at 1027, 1045, 1056, 1075 and 1091 cm^-1 are attributed to the BCl in-plane bending modes. The intense infrared band at 866 cm^-1 is assigned to the tri...
Raman, infrared and near-infrared spectroscopic characterization of the herderi...
Frost, Ray Leslie; Cipriano, Ricardo Augusto Scholz; López, Andrés; Xi, Yunfei; Queiroz, Camila de Siqueira; Belotti, Fernanda MariaNatural single-crystal specimens of the herderite–hydroxylherderite series from Brazil, with general formula CaBePO4(F,OH), were investigated by electron microprobe, Raman, infrared and near-infrared spectroscopies. The minerals occur as secondary products in granitic pegmatites. Herderite and hydroxylherderite minerals show extensive solid solution formation. The Raman spectra of hydroxylherderite are characte...