In-situ Raman spectroscopy of quartz: A pressure sensor for hydrothermal diamond-anvil cell experiments at elevated temperatures

Is quartz a potential indicator of ultrahigh-pressure metamorphism? Laser Raman spectroscopy of quartz inclusions in ultrahigh-pressure garnets

“…Hence, it is a potential Raman geobarometer. The effect of pressure and temperature on quartz Raman bands positions is experimentally well known (Hemley, 1987;Schmidt & Ziemann, 2000). A quartz geobarometer has been calibrated recently on metamorphic quartz from quartz-eclogite, epidote-amphibolite, and amphibolitefacies rocks (Enami et al, 2007).…”

Raman mapping of coesite inclusions in garnet from the Kokchetav Massif (Northern Kazakhstan)

“…Moreover, changes in frequency and linewidth of the 206 and 464 cm −1 A1 Raman modes of quartz have been recently proposed to be used as a pressure sensor [9]. The most intense coesite band at 521 cm −1 (at ambient pressure) has a strong, characteristic pressure shift of 2.9 ± 0.1 cm −1 /GPa [8], while the most intense band of quartz at 464 cm −1 (at ambient pressure) is used for pressure measurements in the present study (characteristic pressure shift of 9 ± 0.5 cm −1 /GPa [9]).…”

“…Moreover, changes in frequency and linewidth of the 206 and 464 cm −1 A1 Raman modes of quartz have been recently proposed to be used as a pressure sensor [9]. The most intense coesite band at 521 cm −1 (at ambient pressure) has a strong, characteristic pressure shift of 2.9 ± 0.1 cm −1 /GPa [8], while the most intense band of quartz at 464 cm −1 (at ambient pressure) is used for pressure measurements in the present study (characteristic pressure shift of 9 ± 0.5 cm −1 /GPa [9]). Applying these geobarometers for "monomineralic" coesite inclusions (following the definition of Parkinson [6]) in refractory minerals such as diamond, garnet, zircons and kyanite from different ultrahigh-pressure metamorphic (UHPM) complexes [5,6,10] and some kimberlitic diamonds [7] reveals several particular features, which can be summarized as follow.…”

“…Both coesite and quartz remain under high pressure as reflected on the shift of their Raman bands. The pressure was determined from the upshift of the dominant coesite and quartz band according to P(GPa) = (ν − 521)/2.9 [8] and P(GPa) = (ν − 464)/9 [9], respectively, and ν is the frequency value for the shifted Raman band. Differences in pressure value for quartz (≤1.5 GPa) and coesite (≤2.4 GPa) within the same inclusions contradict the elastic models proposed by Zhang [11].…”

A Raman spectroscopic study of a fulgurite

“…Colomban (2000Colomban ( , 2001 has described this complex picture in an elegant way, invoking several types of chain, sheet and three-dimensional structures labelled Q 0 -Q 4 , which can be assigned as follows: Q 0 , representing monomer SiO 4 units, with bands in the region 850-800 cm −1 ; Q 1 , representing Si 2 O 7 groups, with a band near 950 cm −1 ; Q 2 , silicate chains with bands in the region of 1100-1050 cm −1 ; Q 3 , silicate sheets with a band near 1100 cm −1 ; and Q 4 , representing SiO 2 and tectosilicates with a band in the range of 1250-1150 cm −1 . Additionally, spectral features may arise from crystalline quartz and its modifications caused by pressure or temperature extremes, for which the parent Si=O band occurs at 465 cm −1 (Jayaraman et al 1987;McMillan et al 1992;Schmidt & Ziemann 2000;Enami et al 2007). Figure 2 presents a typical spectrum collected from a glass bubble within a fulgurite specimen.…”