Copper vanadate minerals found in mediaeval mural paintings
| Autor: | Karin Björling Olausson, Kate Tronner, Anders G. Nord |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Polarized light microscopy
Mineral media_common.quotation_subject chemistry.chemical_element Mineralogy Malachite Conservation Art engineering.material Copper humanities Pigment chemistry Transmission electron microscopy visual_art Tangeite engineering visual_art.visual_art_medium Vanadate media_common Nuclear chemistry |
| Zdroj: | Studies in Conservation. 57:183-186 |
| ISSN: | 2047-0584 0039-3630 |
| Popis: | A yellowish copper vanadate mineral has been found in Swedish mural paintings from the fifteenth century. Small patches occur in malachite-green paint. Thirteen samples from five churches have been analyzed by optical and scanning electron microscopy with energy–dispersive X-ray spectrometry, transmission electron microscopy, X-ray powder diffraction, and polarized light microscopy. The substance is evidently the rather uncommon mineral volborthite, with the chemical formula Cu3V2O7(OH)2.2H2O. Very small quantities have also been noted for another mineral, presumably calcio-volborthite, CaCu(VO4)(OH), also named tangeite. The results show that the conservator should always be observant for pigments not earlier noticed or reported. There are some old mines in Central Europe, e.g. in Germany, which contain malachite as well as copper vanadate minerals, and this is probably the origin of the yellow patches in the paintings. |
| Databáze: | OpenAIRE |
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