FTIR Spectroscopy of the Regulated Asbestos Amphiboles

Abstract

Vibrational spectroscopies (FTIR, Raman) are exceptionally valuable tools for the identification and crystal-chemical study of fibrous minerals, and asbestos amphiboles in particular. Raman spectroscopy has been widely applied in toxicological studies and thus a large corpus of reference data on regulated species is found in the literature. However, FTIR spectroscopy has been mostly used in crystal-chemical studies and very few data are found on asbestos amphiboles. This paper is intended to fill this gap; we report new FTIR data collected on a suite of well-characterized samples of the five regulated amphibole species: anthophyllite, amosite and crocidolite, provided by the Union for International Cancer Control (UICC) Organization, and tremolite and actinolite, from two well-known occurrences. The data from these reference samples have been augmented by results from additional specimens to clarify some aspects of their spectroscopic features. We show that the FTIR spectra in both the OH-stretching region and in the lattice modes region can be effective for rapid identification of the asbestos type.

Mineralogical Characterization and Dissolution Experiments in Gamble’s Solution of Tremolitic Amphibole from Passo di Caldenno (Sondrio, Italy)

“…The XRPD pattern collected for the studied sample could be fully indexed in the C 2/ m space group. Refined cell dimensions were (in Å): a = 9.832 (1), b = 18.065 (4), c = 5.273 (1), β (°) = 104.76 (2), V (Å 3 ) = 905.7 (2), consistent with literature data for amphiboles in the tremolite-actinolite series, see [23]. The XRPD pattern further revealed the presence of a very small amount of chlorite (2 wt.…”

“…The powder FTIR spectrum collected in the OH-stretching region (Figure 5a) shows three well-resolved components at 3672, 3659 and 3643 cm −1 , which can be assigned to different combinations of Mg and Fe 2+ at the M (1,3) sites of the amphibole structure [23,32].…”

“…According to several papers on amphibole spectroscopy (e.g., [23,32]), the relative intensities of the four components in the IR spectrum of a Mg-Fe 2+ -amphibole are directly correlated to the relative amounts of the two substituting cations at the M (1,3) octahedra. The spectrum of Figure 5a has thus been decomposed into single Gaussians following the procedure discussed by Della Ventura [32], such as to derive the integrated intensities of the observed peaks.…”

Asbestos-Based Pottery from Corsica: The First Fiber-Reinforced Ceramic Matrix Composite

“…Figure 3 and Figure 4 show representative FTIR ATR spectra collected on powdered fragments of the shards. Spectrum d f has been recorded on a fiber bundle extracted from sample d. The bands, for instance, the Si-O stretching and bending modes at ~960 (1015 and 1080) and 620 cm −1 ( Figure 3 ), are characteristic of asbestos and similar compounds (amphiboles and pyroxenes) [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. From this first analysis, it can be seen that the samples b and d on the one hand and the samples a and c on the other hand are rather similar, but sample d appears to be more heterogeneous.…”

“…The large number of phases identified by XRPD and the variety of Raman spectra observed are consistent with a firing taking place at low temperature, with a resultant degradation of the pristine mineral occurring without the clear formation of neophases. Trittschack et al [ 18 , 19 , 20 ] observed the intensity decrease of the O-H stretching mode at ~3600–3700 cm −1 over 450 °C (de-hydroxylation) and then the formation of forsterite at a temperature over ~500 °C, with the characteristic doublet seen at ~820–850 cm −1 .…”