Multi-technique analysis of pigments on sandstone sculptures: Renaissance re-painting of a Roman relief

Heritage Science

Table 2 Palette of Pigments on GLAHM.F1

Pigment	Chemical formula	Feature
Lead sulphate	PbSO₄	Ivy tendril Griffin Groove? Griffin eye External border of carved inscription frame Carved inscription frame Letters
Lead tin yellow	Pb₂SnO₄	Griffin eye white (sclera)
Red lead	Dilead(II) lead(IV) oxide: Pb₃O₄	Ivy tendril Griffin groove Griffin eye Flat area beside griffin External border of carved inscription frame Carved inscription frame Inscription panel background Letters
Realgar?	Arsenic(II) sulfide, As₄S₄	Ivy tendril? Griffin groove Griffin eye Flat area beside griffin External border of carved inscription frame Carved inscription frame Inscription background Letters
Red ochre	Iron(III) oxide chromophore (Fe₂O₃ + clay + silica)	Ivy tendril Griffin rosette petal Carved inscription frame Letters
Carbon black	Carbon	Griffin eye (pupil) Griffin groove External border of carved inscription frame Carved inscription frame
Smalt	Cobalt(II) silicate CoO.nSiO₂	Carved inscription frame Inscription panel background Letters
Gold gilding	Au	Carved inscription frame Letters
Orpiment	Arsenic(III) sulfide, As₂S₃	Carved inscription frame Inscription background? Letters