Integrated analytical approach to unveil the secrets of the recently discovered “Sphinx Room”: a new piece of Domus Aurea puzzle

Heritage Science

Table 2 Summary of the vibrational spectroscopy signatures found for each analyzed color pigments, with respective attribution, figures and references

Color	Raman signature (cm⁻¹)	ATR-FTIR signature(cm⁻¹)	DRIFT signature (cm⁻¹)	Attribution		Refs
Blue	426, 1080	519, 565, 598, 668, 754, 906, 1005, 1047, 1082, 1158	1006, 1060, 1250	Egyptian blue	9d, 11a, 13 h/h’, 13i/i’	[34, 44, 55, 56]
Blue	1006	598, 668, 1111, 1620, 3402, 3527	1140, 2120, 2230	Gypsum	9e, 11a, 13i/i’	[34, 41, 42, 57]
Green	–	437, 530	1065, 1205, 1550	Kaolinite, earths?	9d, 13 g/g’	[41, 45, 60, 61]
Green	–	668, 1005, 1165		Egyptian blue?	9d, 13 g/g’	[55]
Yellow	250, 300, 390, 558	470, 539, 798, 910, 1010, 1032, 1083, 1112, 3622, 3648, 3665, 3690	3690, 4524	Yellow ochre	9b, 12b, 13f/f’	[39, 41, 60, 61]
Red	986	606, 630–640, 984, 1070, 1163		Baryte	11c, 13d/d’, 13e/e’	[49]
		680	1415, 1740, 2400	Cerussite	13e/e’	[41, 63]
		430, 464, 531, 1009, 1030, 1130, 1182	1065, 1109	Red ochre	10b, 13d/d’, 13e/e’	[39, 41, 44, 60, 61]
	228, 292, 405, 613		1065, 4525	Red ochre	8f, 10c, 12a	[39, 41, 44, 60, 61]
Brown	674	466, 565		Magnetite	12c	[39, 52, 62]
Brown			1030, 1109, 1550	Red ochre	10a, 13c/c’	[41, 44]
White	*158, 282, 714, 1086*	712, 844, 871, 1085, 1397, 2870	880, 1400, 1795, 2515 + 2590, 4270	Calcite	8e, 9c, 11b, 13b/b’	[34, 40,41,42, 53, 54]
	1006			Gypsum	11b	[34]
	1050			Cerussite	11b	[34]
Black	1375, 1587			Carbon black	11d	[48]

Numbers in bold: laboratory Raman analysis, in italics: in situ Raman analysis. Calcite signature was considered only for white