Dariz, Petra; Schmid, Thomas (2018). Temperaturindikatoren in mittelalterlichen Hochbrandgipsen: Eine Ramanmikrospektroskopische Studie Zeitschrift für Kunsttechnologie und Konservierung, 32(1), pp. 69-78. Wernersche Verlagsgesellschaft
Full text not available from this repository. (Request a copy)In correlation with local deposits, high-fired gypsum was used as binder for masonry and joint mortars or stuccowork in Central Europe in the Early and High Middle Ages. The medieval calcination technology resulted in an assemblage of calcium sulphate phases dehydrated to different degrees and geologically related minor constituents of the gypsum deposit. Microscopy observations of the distinct morphological characteristics serve to roughly distinguish the different subtypes of anhydrite II in not hydrated grains of firing products in the binder matrix and, with it, to estimate the historical calcination conditions, as the proportion of granular anhydrite, considered as insoluble, rises with increasing temperatures at the expense of fibrous anhydrite, which preferably dissolves and hydrates. A novel Raman microspectroscopic approach provides access to the burning history of individual anhydrite grains based on quantifiable spectroscopic changes appearing due to gradual variations of crystallinity, as confirmed by X-ray diffraction analysis of synthesised anhydrites. Beyond that, Raman microspectroscopy was employed for tracing and visualising pyrometamorphic reactions in impurities of the kiln run, which, as mineral thermometry indicates, occurred at temperatures above 800°C: the breakdown of Mg-rich chlorite led to the formation of forsterite, while the thermal decomposition of dolomite to periclase and calcite yielded – after hydration and carbonation – magnesite.
Item Type: |
Journal Article (Original Article) |
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Division/Institute: |
Bern Academy of the Arts Bern Academy of the Arts > Institute Materiality in Art and Culture Bern Academy of the Arts > Institute Materiality in Art and Culture > Technology in Art and Culture |
Name: |
Dariz, Petra and Schmid, Thomas |
Subjects: |
N Fine Arts > NA Architecture N Fine Arts > NB Sculpture N Fine Arts > NK Decorative arts Applied arts Decoration and ornament Q Science > QE Geology T Technology > TH Building construction T Technology > TS Manufactures T Technology > TT Handicrafts Arts and crafts |
ISSN: |
0931-7198 |
Publisher: |
Wernersche Verlagsgesellschaft |
Funders: |
[UNSPECIFIED] Stiftung zur Förderung der Denkmalpflege |
Projects: |
[UNSPECIFIED] Die Phasenzusammensetzung mittelalterlicher Hochbrandgipse |
Language: |
German |
Submitter: |
Petra Dariz |
Date Deposited: |
01 Nov 2023 10:10 |
Last Modified: |
01 Nov 2023 10:10 |
Related URLs: |
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Uncontrolled Keywords: |
mittelalterlicher Hochbrandgips Brenngutkörner Anhydrit Dolomit Forsterit Pyrometamorphose Ramanmikroskopie |
URI: |
https://arbor.bfh.ch/id/eprint/20256 |
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