Fig. 8

Raman spectra of cross section S11 (likely original and overpainting reds). a Raman spectra (λ_exc = 785 nm) of layers 1, 2, and 3 from cross section S4, i.e. multi-layered red paint removed from the sphere’s red flange. b Raman spectra (λ_exc = 785 nm) of layers 4, 5, and 7 from the same cross section. Materials identified in the spectra include PR1 (451, 461, 527, 534, 615, 633, 729, 860, 872, 986, 1001, 1107, 1158, 1167, 1223, 1251, 1257, 1329, 1396, 1429, 1553, 1590, 1609 cm⁻¹), PR3 (339, 380, 616, 722, 737, 745, 798, 843, 986, 1040, 1075, 1187, 1319, 1336, 1395, 1444, 1494, 1554, 1576, 1606, 1620 cm⁻¹), PR4 (314, 357, 402, 420, 426, 591/593, 623/624, 709/710, 737, 768/769, 890/892, 986, 1093, 1116/1117, 1124, 1188, 1224/1227, 1238, 1265/1266, 1315, 1319, 1336, 1396, 1450, 1467, 1486, 1554, 1587 cm⁻¹), PR49 (467, 480, 527, 602, 643, 719, 773, 992, 1096, 1133, 1204, 1214, 1256, 1346, 1411, 1424, 1450, 1463, 1482, 1554, 1601, 1620 cm⁻¹), PR83 (484, 842, 1162, 1190, 1219, 1293, 1328, 1357, 1481, 1520, 1576), lead chromate (364, 822 cm⁻¹), barite (986 cm⁻¹), calcite (1085/1086 cm⁻¹), and gypsum (1007 cm⁻¹). No signal was obtained from layer 6 due to a strong fluorescence emission