75 documents found, page 1 of 8
A vibrational spectroscopic study of the silicate mineral normandite – NaCa(Mn2...
Frost, Ray Leslie; López, Andrés; Theiss, Frederick L.; Cipriano, Ricardo Augusto Scholz; Romano, Antônio WilsonWe have studied the mineral normandite using a combination of scanning electron microscopy with energy dispersive spectroscopy and vibrational spectroscopy. The mineral normandite NaCa(Mn2+,Fe2+)(Ti,Nb,Zr)Si2O7(O,F)2 is a crystalline sodium calcium silicate which contains rare earth elements. Chemical analysis shows the mineral contains a range of elements including Na, Mn2+, Ca, Fe2+ and the rare earth element...
Raman and infrared spectroscopic study of kamphaugite-(Y).
Frost, Ray Leslie; López, Andrés; Cipriano, Ricardo Augusto ScholzWe have studied the carbonate mineral kamphaugite-(Y)(CaY(CO3)2(OH) H2O), a mineral which contains yttrium and specific rare earth elements. Chemical analysis shows the presence of Ca, Y and C. Back scattering SEM appears to indicate a single pure phase. The vibrational spectroscopy of kamphaugite-(Y) was obtained using a combination of Raman and infrared spectroscopy. Two distinct Raman bands observed at 1078 ...
A SEM, EDS and vibrational spectroscopic study of the clay mineral fraipontite.
Theiss, Frederick L.; López, Andrés; Cipriano, Ricardo Augusto Scholz; Frost, Ray LeslieThe mineral fraipontite has been studied by using a combination of scanning electron microscopy with energy dispersive analysis and vibrational spectroscopy (infrared and Raman). Fraipontite is a member of the 1:1 clay minerals of the kaolinite-serpentine group. The mineral contains Zn and Cu and is of formula (Cu,Zn,Al)3(Si,Al)2O5(OH)4. Qualitative chemical analysis of fraipontite shows an aluminium silicate m...
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 Raman and infrared spectroscopic study of the phosphate mineral laueite.
Frost, Ray Leslie; Cipriano, Ricardo Augusto Scholz; López, AndrésA laueite mineral sample from Lavra Da Ilha, Minas Gerais, Brazil has been studied by vibrational spectroscopy and scanning electron microscopy with EDX. Chemical formula calculated on the basis of semi-quantitative chemical analysis can be expressed as (Mn2+0.85,Fe2+0.10Mg0.05)P1.00(Fe3+1.90,Al0.10)P2.00(PO4)2(OH)2_8H2O. The laueite structure is based on an infinite chains of vertex-linked oxygen octahedra, wi...
A SEM, EDS and vibrational spectroscopic study of the tellurite mineral : sonor...
Frost, Ray Leslie; López, Andrés; Cipriano, Ricardo Augusto ScholzWe have undertaken a study of the tellurite mineral sonorite using electron microscopy with EDX combined with vibrational spectroscopy. Chemical analysis shows a homogeneous composition, with predominance of Te, Fe, Ce and In with minor amounts of S. Raman spectroscopy has been used to study the mineral sonoraite an examples of group A(XO3), with hydroxyl and water units in the mineral structure. The free tellu...
A vibrational spectroscopic study of the phosphate mineral vantasselite Al4(PO4...
Frost, Ray Leslie; Cipriano, Ricardo Augusto Scholz; Belotti, Fernanda Maria; López, Andrés; Theiss, Frederick L.We have studied the phosphate mineral vantasselite Al4(PO4)3(OH)3 9H2O using a combination of SEM with EDX and Raman and infrared spectroscopy. Qualitative chemical analysis shows Al, Fe and P. Raman bands at 1013 and 1027 cm 1 are assigned to the PO43 m1 symmetric stretching mode. The observation of two bands suggests the non-equivalence of the phosphate units in the vantasselite structure. Raman bands at 1051...
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...
SEM, EDX and vibrational spectroscopic study of the phosphate mineral ushkovite...
López, Andrés; Cipriano, Ricardo Augusto Scholz; Frost, Ray Leslie; Belotti, Fernanda MariaThe mineral ushkovite has been analyzed using a combination of electron microscopy with EDX and vibrational spectroscopy. Chemical analysis shows the mineral contains P, Mg with very minor Fe. Thus, the formula of the studied ushkovite is Mg3 2+(PO4)2 8H2O. The Raman spectrum shows an intense band at 953 cm 1 assigned to the m1 symmetric stretching mode. In the infrared spectra complexity exists with multiple a...
The molecular structure of the borate mineral szaibelyite MgBO2(OH) : a vibrati...
Frost, Ray Leslie; Cipriano, Ricardo Augusto Scholz; López, Andrés; Belotti, Fernanda MariaWe have studied the borate mineral szaibelyite MgBO2(OH) using electron microscopy and vibrational spectroscopy. EDS spectra show a phase composed of Mg with minor amounts of Fe. Both tetrahedral and trigonal boron units are observed. The nominal resolution of the Raman spectrometer is of the order of 2 cm 1 and as such is sufficient enough to identify separate bands for the stretching bands of the two boron is...