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This is the first application of Raman spectroscopy to the characterization of the kornerupine group of borosilicate minerals. Raman microprobe spectra were collected from [approximately]100 to [approximately]4000 [cm.sup.-1] from 13 samples of kornerupines (from different localities) containing a wide range of boron content (0.02 to 0.84 boron atoms per formula unit of 21.50 atoms). The Raman spectra of the kornerupines are consistent with the structure of the mineral as determined by X-ray diffraction (XRD) analysis, which locates the boron in a tetrahedron at the center of a trimer of corner-sharing tetrahedra and with the presence of only hydroxyl ions (OH) but no molecular water ([H.sub.2]O). Two of the Raman vibrational modes of kornerupines (at [approximately]803 [Delta][cm.sup.-1] and at -884 [Delta][cm.sup.-1]) are sensitive to the presence of boron, and their relative intensities can be used to discriminate between kornerupine and prismatine. based on the intensities of those boron-sensitive bands, the Raman spectroscopic technique could potentially provide a semi-quantitative measure of the boron content of kornerupine.

We have determined major (Si, Zr, Hf), minor (Al, Y, Fe, P), and trace element (Ca, Sc, Ti, Ba, REE, Th, U) concentrations and Raman spectra of a zoned, 200 [[micro]meter] zircon grain in lunar sample 14161,7069, a quartz monzodiorite breccia collected at the Apollo 14 site. Analyses were obtained on a thin section in situ with an ion microprobe, an electron microprobe, and a laser Raman microprobe. The zircon grain is optically zoned in birefringence, a reflection of variable (incomplete) metamictization resulting from zonation in U and Th concentrations. Variations in the concentrations of U and Th correlate strongly with those of other high-field-strength trace elements and with changes in Raman spectral parameters. Concentrations of U and Th range from 21 to 55 ppm and 6 to 31 ppm, respectively, and correlate with lower Raman peak intensities, wider Raman peaks, and shifted Si-O peak positions. Concentrations of heavy rare earth elements range over a factor of three to four and correlate with intensities of fluorescence peaks. Correlated variations in trace element concentrations reflect the original magmatic differentiation of the parental melt [approximately]4 b.y. ago. Degradation of the zircon structure, as reflected by the observed Raman spectral parameters, has occurred in this sample over a range of [Alpha]-decay event dose from [approximately]5.2 x [10.sup.14] to 1.4 x [10.sup.15] decay events per milligram of zircon, as calculated from the U and Th concentrations. This dose is well below the [approximately][10.sup.16] events per milligram cumulative dose that causes complete metamictization and indicates that laser Raman microprobe spectroscopy is an analytical technique that is very sensitive to the radiation-induced damage in zircon.

Researchers illustrate the application of the laser Raman microprobe (LRM) in characterizing the state of the structural order of geologically pertinent carbonaceous materials (CM) varying from kerogen and coals to granulite-facies graphite. Results encourage this application because the spectra facilitate more precise differentiation phases of crystalline development, and because they are more representative of the bulk carbonaceous sample.

HJ Kirsch and AM van den Kerkhof's study on the use of laser Raman microprobe spectroscopy for investigations of fluid inclusions in the C-O-H-N system were interesting but had certain methodological flaws. In particular, certain shortcomings with regard to their analytical approach and interpretation of spectra were evident and could result in the derivation of incorrect compositional and P-V-T information. It is suggested that to make Raman data interpretations more accurate, documentation should also be made on important information such as the values and sources of quantification factors, estimated uncertainties, the method for band position determination and others.

Halites from subsurface cores of the Opeche Shale of North Dakota and the Nippewalla Group of Kansas have been sampled. The rocks were previously shown to have been deposited in continental saline pan systems, and fluid inclusions in the bedded halites are believed to be trapped remnants of Permian lake waters and ground waters. The study has revealed ancient extremely acid lake waters and ground waters.

Author(s): Jill Dill Pasteris (corresponding author); Brigitte Wopenka Fossil remains of the most ancient, minute forms of life on Earth and other planets are hard to recognize. Schopf et al. [...]

Despite numerous analytical studies, the exact nature of the mineral component of bone is not yet totally defined, even though it is recognized as a type of carbonated hydroxylapatite. The present study addresses the hydration state of bone mineral through Raman spectroscopic and thermogravimetric analysis of 56 samples of carbonated apatite containing from 1 to 17 wt% CO3, synthesized in H2O or D2O. Focus is on the relation between the concentration of molecular water (as distinguished from hydroxyl ions) and the concentration of carbonate in the apatite. Raman spectra confirm the presence of molecular water as part of the crystalline structure in all the aqueously precipitated carbonated apatites. TGA results quantitatively document that, regardless of the concentration of carbonate in the structure, all hydroxylapatites contain ~3 wt% of structurally incorporated water in addition to multiple wt% adsorbed water. We spectroscopically confirmed that natural bone mineral also contains structurally incorporated molecular H2O based on independent analyses of bone by means of spectral stripping (subtracting the spectrum of collagen from that of bone) and chemical stripping (chemically removing the collagen content of bone prior to analysis). Taken together, the above data support a model in which water molecules densely populate the apatite channels regardless of the abundance of hydroxyl vacancies. We hypothesize that water molecules keep the apatite channels stable even when 80% of the hydroxyl sites are vacant (typical in bone), hinder carbonate ions from substituting for hydroxyl ions in the channels, and help regulate chemical access to the channels (e.g., ion exchange, entry of small molecules). Our results show that bone apatite is not a "flawed hydroxylapatite," but instead a definable mineralogical entity, a combined hydrated-hydroxylated calcium phosphate phase of the form Ca10-x[(PO4)6-x(CO3)x](OH) 2-x⋅nH2O, where n ~1.5. Water is therefore not an accidental, but rather an essential, component of bone mineral and other natural and synthetic low-temperature carbonated apatite phases. [ABSTRACT FROM AUTHOR]

- Raman analyses were performed of individual micrometer-sized fragments of material returned to Earth by the NASA Stardust mission to comet 81P/Wild 2. The studied fragments originated from grains ( C2054,0,35,91,0 and C2092,6,80,51,0) of two different penetration tracks that occurred in two different silica aerogel collector cells. All fragments of both particles have Raman spectra characteristic of amorphous sp2-bonded carbon that are in general agreement with the results published in previous Stardust particle studies. The present study, however, does not focus on the discussion of specific details of the D and G band parameters, but rather reports on additional information that can be obtained from returned Stardust samples via Raman spectroscopy. Most notably, the Raman spectra show that all analyzed fragments of the particles were contaminated with the capture medium (i.e., aerogel). The silica aerogel is laced with organic aliphatic and aromatic hydrocarbon impurities that resulted in strong bands in the ∼ 2900 Δcm−1 spectral range (C-H stretching modes). Aerogel bands are also found in the 1000-1600 Δcm−1 spectral range, where they overlap with the bands of the amorphous sp2-bonded carbon. The peaks associated with the aerogel contamination differ between the two grains that originated from two different aerogel cells. In addition to the bands due to aerogel contamination and the always present sp2-bonded carbon bands, fragments of particle C2092,6,80,51,0 also show Raman peaks for pyrrhotite and Fa30Fo70 olivine. Complete (up to 4000 Δcm−1) raw and baseline-corrected Raman spectra of the Stardust particles are shown and discussed in detail. [ABSTRACT FROM AUTHOR]