title: Phosphorus K-edge XANES spectroscopy of mineral standards.
abstract: Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy was performed on phosphate mineral specimens including (a) twelve specimens from the apatite group covering a range of compositional variation and crystallinity; (b) six non-apatite calcium-rich phosphate minerals; (c) 15 aluminium-rich phosphate minerals; (d) ten phosphate minerals rich in either reduced iron or manganese; (e) four phosphate minerals rich in either oxidized iron or manganese; (f) eight phosphate minerals rich in either magnesium, copper, lead, zinc or rare-earth elements; and (g) four uranium phosphate minerals. The identity of all minerals examined in this study was independently confirmed using X-ray powder diffraction. Minerals were distinguished using XANES spectra with a combination of pre-edge features, edge position, peak shapes and post-edge features. Shared spectral features were observed in minerals with compositions dominated by the same specific cation. Analyses of apatite-group minerals indicate that XANES spectral patterns are not strongly affected by variations in composition and crystallinity typical of natural mineral specimens.
authors.affiliation: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332-0340, USA.
authors.forename: Ellery D
authors.initials: ED
authors.lastname: Ingall
authors.forename: Jay A
authors.initials: JA
authors.lastname: Brandes
authors.forename: Julia M
authors.initials: JM
authors.lastname: Diaz
authors.forename: Martin D
authors.initials: MD
authors.lastname: de Jonge
authors.forename: David
authors.initials: D
authors.lastname: Paterson
authors.forename: Ian
authors.initials: I
authors.lastname: McNulty
authors.forename: W Crawford
authors.initials: WC
authors.lastname: Elliott
authors.forename: Paul
authors.initials: P
authors.lastname: Northrup