Distribution changes of Mn2+ and Fe3+ on weathered marble surfaces measured by EPR spectroscopy

Detection of Ancient Marble Forgery: Techniques and Limitations*

“…Furthermore, EPR has shown that while the total amount of iron (oxides and silicates included) on marble surfaces increases, the amount of iron (Fe 3+ ) substituting for Ca 2+ in the CaCO 3 lattice decreases, with the surface values varying from 80% to 0.5% of the bulk value (Fig. 5; Polikreti and Maniatis 2004). The main cause of this dramatic depletion of iron is most probably the dissolution and subsequent recrystallization of CaCO 3 .…”

“…5; Polikreti and Maniatis 2004). EPR spectroscopy is the only technique used in marble studies that can distinguish ions in different crystal environments.…”

“…The marble is Proconessian. The decrease in Fe 3+ replacing Ca 2+ in the CaCO 3 lattice can only be measured by EPR spectroscopy and is a crucial observation in favour of authenticity (from Polikreti and Maniatis 2004). is a 'purification' process and causes a reduction in the concentration of elements hosted in the lattice, relative to the primary crystals.…”

A wide‐line low frequency electron paramagnetic resonance spectrometer

“…[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Many pigments used in paintings are paramagnetic. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Many pigments used in paintings are paramagnetic.…”

“…Electron paramagnetic resonance spectroscopy is a useful tool for studying objects with cultural heritage importance. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Many pigments used in paintings are paramagnetic. Many clays contain paramagnetic metals, some of which become ferromagnetic upon firing.…”