Table 1 Summary of findings in the samples’ layers
Sample | Type | Notes | No. of layers | Layers | Plaster | Interface | Coating | Overpaint |
|---|---|---|---|---|---|---|---|---|
1 | Dust | Fibres and mixture of organic and inorganic material | – | – | – | – | – | – |
2 | Plaster from the inner bulk |  | – | – | Calcium sulfate, calcium carbonate, clay minerals, Al, Mg, Si, diterpenic resin | – | – | – |
3 | Cross-section |  | 3 | 2. Dark layer | Calcium sulfate, calcium carbonate, clay minerals, Mg, diterpenic resin | Intermediate of plaster and dark layer | Mostly Si and Al; Fe, Ti and traces of Na, Cl and K, diterpenic resin | – |
1. Yellowish and undefined layer | ||||||||
0. Plaster bulk | ||||||||
4 | Cross-section | Edge area of sampling | 4 | 3. Purple layer | Calcium sulfate, calcium carbonate, clay minerals, Mg, diterpenic resin | Intermediate of plaster and dark layer | Mostly Si and Al, traces of K, Ba, Zn, Cl and P, diterpenic resin | Fe, Si and Ti, traces of K, Ba, Zn, Cl and P, drying oil modified alkyd paint |
2. Dark layer | ||||||||
1. Yellowish and undefined layer | ||||||||
0. Plaster bulk | ||||||||
5 | Cross-section |  | 3 | 2. Dark layer | Calcium sulfate, calcium carbonate, clay minerals, Mg, Ti, diterpenic resin | Intermediate of plaster and dark layer | Mostly Si and Al, traces of Mg, Ti, Na, Fe and K, diterpenic resin | – |
1. Yellowish and undefined layer | ||||||||
0. Plaster bulk | ||||||||
6 | Cross-section | Area of repair | 3 | 2. Dark layer | Calcium sulfate, calcium carbonate, clay minerals, Mg, Ti, traces of K and Fe, organic medium | Intermediate of plaster and dark layer | Mostly K, Fe, Si and Al, traces of Na, Pb and Cl, organic medium | – |
1. Yellowish and undefined layer | ||||||||
0. Plaster bulk | ||||||||
7 | Cross-section | Area of repair | 2 | 1. Yellowish and undefined layer with large orange and black particles | Calcium sulfate, calcium carbonate, clay minerals, organic medium | – | Mostly Fe and Ba, traces of Mg, K and Cl, organic medium | – |
0. Plaster bulk | ||||||||
8 | Cross-section | Fluorescent varnish | 4 | 3. Varnish | Calcium sulfate, calcium carbonate, clay minerals, Mg, Cl, diterpenic resin, possibly additional triterpenic resin or birch | Intermediate of plaster and dark layer | Mostly Si and Al, traces of K, Fe and Na, diterpenic resin, possibly additional triterpenic resin or birch | – |
2. Dark layer | ||||||||
1. Yellowish and undefined layer | ||||||||
0. Plaster bulk | ||||||||
9 | Cross-section |  | 3 | 2. Dark layer | Calcium sulfate, calcium carbonate, clay minerals, Mg, Al, Sr and Fe, diterpenic resin, possibly additional triterpenic resin or birch | Intermediate of plaster and dark layer | Mostly Si, Al, Mg, Sr and Fe, traces of K and Ti, diterpenic resin, possibly additional triterpenic resin or birch | – |
1. Yellowish and undefined layer | ||||||||
0. Plaster bulk | ||||||||
10 | Cross-section |  | 3 | 2. Dark layer | Calcium sulfate, calcium carbonate, clay minerals, Mg, organic medium | Intermediate of plaster and dark layer | Mostly Si and Al, traces of K and Cl, organic medium | – |
1. Yellowish and undefined layer | ||||||||
0. Plaster bulk | ||||||||
11 | Cross-section |  | 4 | 3. Varnish | Calcium sulfate, calcium carbonate, clay minerals, Mg, organic medium | Intermediate of plaster and dark layer | Mostly Si and Al, traces of Fe and Mg, organic medium | – |
2. Dark layer | ||||||||
1. Yellowish and undefined layer | ||||||||
0. Plaster bulk | ||||||||
12 | Cross-section | Fluorescent varnish | 4 | 3. Varnish | Calcium sulfate, calcium carbonate, clay minerals, Mg | Intermediate of plaster and dark layer | Mostly Si and Al, traces of P, Cl and Fe, organic medium | – |
2. Dark layer | ||||||||
1. Yellowish and undefined layer | ||||||||
0. Plaster bulk | ||||||||
13 | Cross-section | Fluorescent varnish | 4 | 3. Varnish | Calcium sulfate, calcium carbonate, clay minerals, Mg, diterpenic resin | Intermediate of plaster and dark layer | Mostly Si and Al, traces of Fe, Mg, Cl, Ti and Na, diterpenic resin | – |
2. Dark layer | ||||||||
1. Yellowish and undefined layer | ||||||||
0. Plaster bulk |