The aim of this project was to achieve a deep understanding of the mechanisms by
which Baltic amber degrades, in order to develop techniques for preventive
conservation of archaeological amber objects belonging to the National Museum of
Denmark’s collections.
To examine deterioration of Baltic amber, a starting point was to identify and monitor
surface and bulk properties which are affected during degradation.
The way to operate consisted of the use of accelerated ageing to initiate degradation
of raw Baltic amber samples in different conditions of relative humidity, oxygen
exposure or pH and, successively, of the use of non/micro-destructive techniques to
identify and quantify changes in visual, chemical and structural properties.
A large piece of raw Baltic amber was used to prepare several test samples for two
different kinds of accelerated ageing: thermal-ageing and photo-ageing.
During the ageing, amber samples were regularly examined through several analytical
techniques related to different information: appearance/colour change by visual
examination, photography and colorimetry; chemical change by infrared
spectroscopy, Raman spectroscopy and elemental analysis; rate of oxidation by
oxygen measurement; qualitative analysis of released volatiles by gas
chromatography – mass spectrometry.
The obtained results were analysed through both critical evaluation and statistical
study.
After the interpretation of the achieved data, the main relations between amber and
environmental factors during the degradation process became clearer and it was
possible to identify the major pathways by which amber degrades, such as hydrolysis
of esters into alcohols and carboxylic acids, thermal-oxidation and photo-oxidation of
terpenoid components, depolymerisation and decomposition of the chemical structure.
At the end it was possible to suggest a preventive conservation strategy based on the
control of climatic, atmospheric and lighting parameters in the environment where
Baltic amber objects are stored and displayed.
| Identifer | oai:union.ndltd.org:unibo.it/oai:amsdottorato.cib.unibo.it:2259 |
| Date | 12 October 2009 |
| Creators | Pastorelli, Gianluca <1975> |
| Contributors | Richter, Jane |
| Publisher | Alma Mater Studiorum - Università di Bologna |
| Source Sets | Università di Bologna |
| Language | English |
| Detected Language | English |
| Type | Doctoral Thesis, PeerReviewed |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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