Green copper pigments of old Russian frescoes

Abstract

The study of frescoes dating back to the early sixteenth century in the Cathedral of the Nativity of the Virgin of the 8t Pherapont monastery revealed the presence of green copper pigments such as malachite, atacamite, posnjakite and natural pseudo-malachite.The minerals were identified by light microscopy, X-ray microspectrometry and X-ray diffraction.

New Insights into Synthetic Copper Greens: The Search for Specific Signatures by Raman and Infrared Spectroscopy for Their Characterization in Medieval Artworks

“…We tested this variation because we know that many craft recipes have not been documented in written sources, but were part of an anonymous craft "savoir faire" that has been lost. It was very exciting to find that this kind of formulation was detected in works of art ranging from panel painting to medieval illuminations, and from Europe to Persia [10][11][12][13]. We consider that one of our main contributions lies in the integration of our knowledge on craft recipes that describe the manufacture and preparation of paint materials with the state-of-the-art research on the mechanisms of atmospheric corrosion of metals.…”

On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments

“…Brochantite was identified as a pigment as well [1], but it can transform into the more stable polymorphs, antlerite, langite or posnjakite, according to the given conditions of relative humidity, inorganic pollutants (SO x ) and biological activity (affecting the pH and the type of acids) [127,129,168]. Posnjakite was also identified as a pigment [162,169]. Brochantite, as well as posnjakite and antlerite are also intermediate reaction products between copper carbonates and copper oxalates, and are therefore sensitive to oxalic acid [127].…”

Material and diagnostic characterization of 17th century mural paintings by spectra‐colorimetry and SEM‐EDS: An insight look at José de Escovar Workshop at the CONVENT of Na Sra da Saudação (Southern Portugal)

“…Although the earliest recipe for posnjakite dates from the late eighteenth century or early nineteenth century, this copper sulfate could possibly appear as an intermediated product in the mixtures of salts obtained by historical recipes . In this case, despite the identical optical characteristics of natural and artificial posnjakite, the latest should have different and rather uniform morphological features . In this painting, however, the pigment particles morphology points in another direction (Fig.…”

“…29 In this case, despite the identical optical characteristics of natural and artificial posnjakite, the latest should have different and rather uniform morphological features. 27,28 In this painting, however, the pigment particles morphology points in another direction (Fig. 15).…”

“…Where does the copper sulfate comes from? According to Naumova et al 27,28 and, more recently, Svarcov a et al 29 natural posnjakite is difficult to find in nature and only within a complex and specific mineral oxidation zones of copper deposits. The most likely origin should be artificial.…”