TY - JOUR

T1 - Raman spectroscopy of various phosphate minerals and occurrence of tuite in the Elga IIE iron meteorite

AU - Litasov, Konstantin D.

AU - Podgornykh, Nikolay M.

PY - 2017/11/1

Y1 - 2017/11/1

N2 - The Raman spectra of phosphate minerals: apatite, merrillite, panethite, brianite, czochralskiite, maricite, new phosphate with composition of Na2Fe(Mg,Ca)(PO4)2 and high-pressure phase tuite from the Elga IIE iron meteorite are characterized. Panethite, brianite, czochralskiite and new Na-Fe phosphate were described for the first time. The basic features of all studied phosphates include strong ν1 symmetric stretching mode of PO4 3− ions at 950–990 cm−1, antisymmetric ν3 vibrations in the 1000–1175 cm−1 region and weak bands in the 400–500 cm−1 region, which correspond to ν2 bending mode and in the 550–640 cm−1 region, related to ν4 bending mode. Weak bands at less than 300 cm−1 represent lattice modes. Most of the studied phosphates have three non-equivalent positions of phosphorus atoms in the crystal structures and can be derived from glaserite, K3Na(SO4)2, arrangement. Two or three of non-equivalent [PO4] tetrahedra typically correspond to two or three strong bands in the region of ν1 vibrations. High-pressure mineral tuite has similar composition and was formed after merrillite. P-O vibrations in equivalent [PO4] tetrahedra produce major Raman band of tuite at 972 cm−1. The Elga parent-body experienced a shock pressure of at least 12–15 GPa according to minimum pressures of tuite formation in the static high-pressure experiments. This is the first finding of tuite in iron meteorites and the only second finding of high-pressure mineral in them.

AB - The Raman spectra of phosphate minerals: apatite, merrillite, panethite, brianite, czochralskiite, maricite, new phosphate with composition of Na2Fe(Mg,Ca)(PO4)2 and high-pressure phase tuite from the Elga IIE iron meteorite are characterized. Panethite, brianite, czochralskiite and new Na-Fe phosphate were described for the first time. The basic features of all studied phosphates include strong ν1 symmetric stretching mode of PO4 3− ions at 950–990 cm−1, antisymmetric ν3 vibrations in the 1000–1175 cm−1 region and weak bands in the 400–500 cm−1 region, which correspond to ν2 bending mode and in the 550–640 cm−1 region, related to ν4 bending mode. Weak bands at less than 300 cm−1 represent lattice modes. Most of the studied phosphates have three non-equivalent positions of phosphorus atoms in the crystal structures and can be derived from glaserite, K3Na(SO4)2, arrangement. Two or three of non-equivalent [PO4] tetrahedra typically correspond to two or three strong bands in the region of ν1 vibrations. High-pressure mineral tuite has similar composition and was formed after merrillite. P-O vibrations in equivalent [PO4] tetrahedra produce major Raman band of tuite at 972 cm−1. The Elga parent-body experienced a shock pressure of at least 12–15 GPa according to minimum pressures of tuite formation in the static high-pressure experiments. This is the first finding of tuite in iron meteorites and the only second finding of high-pressure mineral in them.

KW - apatite

KW - iron meteorite

KW - merrillite

KW - phosphate

KW - tuite

KW - MERRILLITE

KW - 6 GPA

KW - CA3(PO4)2

KW - STISHOVITE

KW - CRYSTAL-CHEMISTRY

KW - PRESSURE

KW - WHITLOCKITE

KW - PHASE

KW - DENSE POLYMORPH

KW - MARTIAN METEORITE

UR - http://www.scopus.com/inward/record.url?scp=85012992007&partnerID=8YFLogxK

U2 - 10.1002/jrs.5119

DO - 10.1002/jrs.5119

M3 - Article

AN - SCOPUS:85012992007

VL - 48

SP - 1518

EP - 1527

JO - Journal of Raman Spectroscopy

JF - Journal of Raman Spectroscopy

SN - 0377-0486

IS - 11

ER -