carmine

Evidence

"Analysis of the purple colour gave a complex Raman spectrum with bands at 1691, 1481, 1316, 1294, 1104, 1004 and 542 cm−1 (Fig. 10f), very similar to the reference ones for carmine (carminic acid, C22H20O13)"

Remarks

Carmine was identified specifically on the 17th-century copy of the Shah namah (MSL/1876/691) for purple tones (p. 27). Organic reds like carmine and madder have been previously identified on some Persian paintings but are often more difficult to detect than inorganic pigments due to potential fluorescence (p. 2, 27).