The role of intensity and instrument sensitivity in Raman mineral identification

Abstract

Mineral identification is a basic and common element of investigations in a wide variety of fields that deal with natural crystalline materials and their synthetic analogues. Raman spectroscopy has been shown to be effective for mineral identification through spectral pattern matching and, in addition, offers a number of practical advantages over established mineral-identification technologies. In order to make Raman technology accessible to the user community that routinely requires a mineral identification tool, the systematics of Raman spectra of minerals must be investigated and incorporated into instrument design, software design, and methodology documentation. This paper quantifies the range of Raman intensities that can be expected from natural minerals and investigates the incorporation of this information into instrument standards and analytical methodology. For this study, 7978 Raman spectra representing 2159 mineral species were extracted from the RRUFF database (http://rruff.info) and separated into four instrument-specific groups. Pseudo-logarithmic histograms show that Raman intensities of minerals can span four orders of magnitude, and opaque minerals tend to have one order of magnitude lower intensities than non-opaque minerals. Examples of inter-instrument comparisons show that instrument sensitivity can vary by a factor of 35. An experiment investigating the data quality required for mineral identification indicates that a functional minimum signal-to-noise ratio is 15. The results of this study can be used to design data collection strategies. The minerals quartz and pyrite are shown to represent the high-frequency center of intensity distributions for non-opaque and opaque minerals, respectively. The requirements for a relevant instrument-sensitivity standard are also discussed.

Recent advances in linear and non‐linear Raman spectroscopy. Part X

“…The minerals quartz and pyrite were shown to represent the high‐frequency center of intensity distributions for non‐opaque and opaque minerals, respectively. The requirements for a relevant instrument‐sensitivity standard were also discussed . Bathgate and co‐workers described a Raman, FTIR and XRD study of Icelandic tephra minerals with implications for Mars exploration.…”

“…The requirements for a relevant instrumentsensitivity standard were also discussed. [112] Bathgate and coworkers described a Raman, FTIR and XRD study of Icelandic tephra minerals with implications for Mars exploration. They found that the FTIR results gave essential information on the presence of H 2 O in the samples.…”

11th International GeoRaman Conference

“…Korsakov et al undertook Confocal two‐dimensional and three‐dimensional Raman imaging of the Kokchetav metamorphic diamonds from different rock types which these results showed that those various diamonds had different crystal quality with complex internal morphologies associated with defects. The paper by Bartholomew et al investigates the potential of Raman spectroscopy as the number one instrument for mineral identification in the Geosciences. They quantify the range of Raman intensities that can be expected from natural mineral samples and investigate the incorporation of this information into instrument standards and analytical methodology to design data collection strategies across Geoscience laboratories.…”

Raman Spectroscopy Study of Phosphorites Combined with PCA-HCA and OPLS-DA Models

“…Raman spectroscopy is a powerful, fast, and nondestructive experimental technique, which has been extensively applied not only in basic scientific researches, but also for practical applications. It can provide physical, chemical, and structural characteristics of investigated samples [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In the past decade, Raman spectroscopy has been applied for quantitative and qualitative studies of various types of minerals.…”

“…Dörfer et al [16] proposed four different ways to generate quantitative and qualitative mineral information based on a Raman mapping experiment. Bartholomew et al [17] showed that Raman spectroscopy is effective for mineral identification through spectral pattern matching and it offers a number of practical advantages over established mineral-identification technologies. Lopez-Reyes et al [18] used Raman Laser Spectrometer technology to quantify and determine the mineral concentration of rock powder in Mars exploration.…”