Modelling clay materials used in artworks: an infrared spectroscopic investigation

Table 4 Major infrared band assignments for modelling clay samples from Boonma artwork

Wavenumber/cm⁻¹	Band assignments	References
712	CaCO₃ C–O bending	[6,7,8,9]
718, 729	Paraffin C–H rocking	[10, 11, 13, 14]
849, 876	CaCO₃ C–O bending	[6,7,8,9]
700–950	Kaolinite O–H bending, Si–O stretching	[21, 26]
800–1200	Kaolinite Si–O stretching	[21, 26]
1000–1300	Oxidation products C–O and C–C stretching	[17, 23]
1378	Paraffin C–H bending	[10, 11, 13, 14]
1420	CaCO₃ C–O stretching	[6,7,8,9]
1461, 1472	Paraffin C–H bending	[10, 11, 13, 14]
1600–1700	Water O–H bending	[23]
1600–1700	Oxidation products C=O stretching	[16,17,18, 23]
1785	CaCO₃ C=O stretching	[6,7,8,9]
2525	CaCO₃ overtone/combination band	[7, 8]
2848, 2880, 2915, 2951	Paraffin C–H stretching	[10, 11, 13, 14]
3100–3600	Water O–H stretching	[23]
3100–3600	oxidation products O–H stretching	[23]
3624, 3638, 3688	Kaolinite O–H stretching	[21, 26]