Characterization of Chrysotile, Antigorite and Lizardite by Ft-Raman Spectroscopy

Abstract

We analyzed samples of antigorite, lizardite and fibrous chrysotile, three representative minerals of the serpentine group, to determine their chemical and structural properties, and their FT-Raman spectra. The low-frequency region of the spectrum (1200-200 cm -1 ), which corresponds to the lattice-vibration modes, was then analyzed, and the observed bands attributed, on the basis of our results. Raman spectroscopy thus proves useful in identifying the three mineral species, despite their strong similarities in structure and chemical composition. The symmetric stretching modes of the Si-O b -Si linkages vibrate at different frequencies in chrysotile and antigorite, whereas chrysotile and lizardite can easily be identified by analyzing the vibrations of the OH-Mg-OH groups and the bands in the range 550-500 cm -1 .

Raman Micro-Spectroscopy Identifies Carbonaceous Particles Lying on the Surface of Crocidolite, Amosite, and Chrysotile Fibers

“…Figure 3b shows a typical collected Raman spectrum. The bands detected in the 1200-100 cm −1 spectral range, except the band at 1120 cm −1 , agree with the data in Rinaudo et al, 2003 andGroppo et al, 2006 [6,57]. Directing the laser beam onto the dark areas, specific bands ascribable to carbonaceous phases were detected, Figure 3b.…”

“…In fact, analyzing different regions of the same bundle of crocidolite, amosite, and chrysotile fibers, showing different colors under OM, the presence of particles, micrometric in size, showing different chemical composition and lying on the fiber surface could be proved. Considering the Raman spectra recorded in dark regions, for the spectral range corresponding to lattice vibrations of the crocidolite, amosite, and chrysotile minerals 1200-100 cm −1 , the observed data (Table 1) [5,6,57], except for the band at 1120 cm −1 on chrysotile spectra, Figure 1b, Figure 2b and Figure 3b. New bands were observed in the spectral range of 4000-1200 cm −1 , where bands produced by carbonaceous phases occur [48][49][50][51][52][53][54][55][56].…”

“…There are six fibrous mineral phases regulated by Law as "asbestos", five belonging to the amphibole family including tremolite asbestos, actinolite asbestos, anthophyllite asbestos, cummingtonite-grunerite asbestos (amosite), riebeckite asbestos (crocidolite), and one belonging to serpentine, which is chrysotile [1][2][3][4][5][6]. Certainly, chrysotile, crocidolite, and amosite have been the most intensively used for production of different kinds of materials.…”

Multi-Analytical Approach for Identifying Asbestos Minerals In Situ

“…Indeed, the Raman spectra show the patterns reported in Figure 5a, which unambiguously identify chrysotile [62,63]. In fact, it is possible to observe the bands of the chrysotile at 694, 387 and 232 cm −1 (Figure 5a).…”

Inclusions of black-green serpentine jade determined by Raman spectroscopy

“…The band at 373 cm −1 is ascribed to the bending modes of [SiO 4 ] tetrahedron; the intense band at 681 cm −1 is produced by the symmetric stretching vibration of Si O b Si, whereas the band at 1045 cm −1 is attributed to the antisymmetric stretching vibration of Si O b Si. In the four weak bands [15], the band at 130 cm −1 corresponds to the O Si O symmetric bending vibration, the band at 456 cm −1 is ascribed to the bending vibration of Si O, the band at 528 cm −1 is ascribed to the deformation vibration of SiO 4 AlO 4 and the band at 641 cm −1 is assigned to the OH Mg OH translation mode [16].…”