Table 1.
Minerals identified in the paint layer by Raman microspectroscopy.
| Mineral phase | Formula | Source/interpretation |
|---|---|---|
| > 1% of the assigned Raman spectra: | ||
| Cuprorivaite | CaCuSi4O10 | Synthesis |
| Calcite | CaCO3 | Quartz sand/carbonation |
| Amorphous carbon | C | Underpainting |
| Quartz | SiO2 | Quartz sand |
| Feldspars | M(I)xM(II)1-xAl2-xSi2+xO8 | Quartz sand |
| < 1% of the assigned Raman spectra: | ||
| Syngenite | K2Ca(SO4)2·H2O | Application (plant ash) |
| Weddellite (oxalate) | Ca(C2O4)·2H2O | Ageing (microorganisms) |
| Augite-diopside | (Ca,Mg,Fe)2Si2O6 | Quartz sand |
| Aegirine | NaFeSi2O6 | Quartz sand |
| Chalcocite | Cu2S | Copper ore |
| Natrojarosite | NaFe3(SO4)2(OH)6 | Copper ore |
| Basic copper arsenate | Cux(AsO4)y(OH)2x-3y | Copper ore |
| Cassiterite | SnO2 | Copper ore |
| Magnetite | Fe3O4 | Quartz sand/copper ore |
| ≤ 1‰ of the assigned Raman spectra: | ||
| Cristobalite | SiO2 | Quartz sand/synthesis (?) |
| Apatite | Ca5(PO4)3(F,OH) | Quartz sand/copper ore/synthesis |
| Osarizawaite | PbCuAl2(SO4)2(OH)6 | Copper ore |
| Eskolaite | Cr2O3 | Copper ore |
| Malayaite | CaSnOSiO4 | Synthesis (copper ore) |
| Polyhalite | K2Ca2Mg(SO4)4·2H2O | Application (plant ash) |
| Anatase | TiO2 | Quartz sand/copper ore/synthesis |
| Copper oxide | CuxO | Synthesis (copper ore) |
| Aragonite | CaCO3 | Carbonation |
| Lead oxide | PbOx | Synthesis (copper ore) |
| Dolomite | CaMg(CO3)2 | Quartz sand |
| Jacobsite | MnFe2O4 | Copper ore |
| Hematite | Fe2O3 | Quartz sand/synthesis |
| Silicate glass | “SiO2” | Synthesis (quartz sand) |