Naslov
Analysis on pigment, frescoes and mortars by electron and light microscopy

Autori
Zubin, Tea ; Grozdanić, Vedrana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, stručni

Izvornik
10th Multinational Congress on Microscopy Proceedings / Societa Italiana Scienze Microscopiche - , 2011, 701-702

Skup
10th Multinational Congress on Microscopy

Mjesto i datum
Urbino, Italija, 04.09.2011

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
scanning electron microscopy ; (SEM) ; energy dispersive analysis (EDX) ; frescoes ; pigments ; mortars

Sažetak
In 2010 archaeological excavations in S. Martin’s Square in Umag (Croatia) successfully unearthed St. Martin’s church, including its necropolis and about 2700 well conserved frescoes’ fragments. Since the archaeological stratigraphy in the excavated site included several periods (from antiques through medieval period till today) it was important to determine the building phases of the found structures in order to define the historical period of the frescoes’ creation. Samples of mortars, plasters and frescoes were taken from different points in the site following instructions of archaeologists. Samples were embedded in epoxy resin and polished sections were made and examined by light microscope OLYMPUS SZX10 in order to determine phases of construction in the excavated site. Each specimen was observed and photographed at same magnifications. In total, 14 characteristics of layers, matrixes and grains of each sample were described according to the norm NORMAL 12/83 ICR. Samples were then compared to define analogy between samples or single layers. Small fragments of frescoes were then analyzed with scanning electron microscope FEG QUANTA 250 FEI by energy dispersive microanalysis (SEM/EDX) without sampling, to determine pigment composition. For this purpose fragments with several colours were chosen in order to point out the differences in composition of used pigments. Elemental map showed the composition of the red pigment, identified as red ocher (hematite and aluminosilicates). The grey pigment was identified as carbon black while the yellow one was supposed to be yellow ocher (limonite and aluminosilicates). The study of the plasters and mortars revealed two phases of construction ; the first one in which the church was build and the frescoes painted, followed by phase of church renewal, when plasters with frescoes were used as groundwork- partially removed from the walls, grounded and used for the church renewal. The analysis of pigments and frescoes referred on skilled workers who knew the technique of a true a fresco wall painting and who used suitable, fine grounded and resistant pigments.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Arheologija

Napomena
Poster je nagrađen u kategoriji Material Science.

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