http://http://dspace.unitus.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Sun, 19 May 2013 11:09:14 GMT 2013-05-19T11:09:14Z http://hdl.handle.net/2067/1325 Title: Raman spectroscopic analysis of azurite blackening Authors: Mattei, Elisabetta; De Vivo, Giulia; De Santis, Alberto; Gaetani, Carolina; Pelosi, Claudia; Santamaria, Ulderico Abstract: Azurite is a basic copper carbonate pigment largely employed in painting realization. The areas painted with azurite are easily alterable and are often less resistant than the other parts of artworks. The azurite alteration in a black pigment, the copper oxide (tenorite), has been studied by micro-Raman spectroscopy. The blackening can be due to thermal or chemical alterations: in the second case the alterations being due to the presence of alkaline conditions. Laser-induced degradation of azurite has been studied as a function of the grain size. The results show that the temperature of the grains decreases as the size increases, and azurite degrades into tenorite only below the critical value of 25 μm. To study the chemical alteration of azurite, the pigment has been applied on the plaster of terracotta samples and analyzed at different pH values by micro-Raman spectroscopy. As opposed to most part of the analytical techniques, it can detect the presence of both azurite and tenorite molecules in the same micro areas, and provides a valuable tool to determine azurite degradation. Thu, 31 Jan 2008 23:00:00 GMT http://hdl.handle.net/2067/1325 2008-01-31T23:00:00Z