Conservation – Page 2 – Lightsources.org

Determining the impact of post-conservation corrosion

2018/03/092018/03/08

When King Henry VIII’s flagship, the Mary Rose, sank off Portsmouth in 1545, it took with it 1248 iron cannonballs. Since the excavation of the shipwreck (from 1979-1983), the cannonballs have been conserved in different ways, offering a unique opportunity to study different conservation methods.

Humans have been using iron to make weapons, tools and ceremonial items for more than 20,000 years, but once these objects have been excavated they are at risk from corrosion, which can be accelerated in the presence of chlorine. Each recovered artefact has to be conserved to prevent it from deteriorating in the presence of air and water. Until now, a comparison of the effectiveness of different conservation methods has been hampered by the variable nature of both the artefacts found, and the environment in which they were buried.

Image: Dr Eleanor Schofield, Dr Giannantonio Cibin and Hayley Simon with iron shot and samples on Diamond’s B18 beamline.
Credit: Diamond Light Source

Technique provides insights into historic maritime artefact

2018/03/052018/03/05

Recently an advanced X-ray imaging technique was used on a historic pewter plate linked to the early exploration of Australia by the Dutch in the 17th century. X-ray fluorescence (XRF) has proven to be a highly useful analytical tool for the study of cultural objects, such as works of art and artefacts.

“The non-destructive analysis can provide information about how the objects were made, their composition and insight for conservation strategies,” said XRF beamline scientist Dr Daryl Howard.
“The fast detector on the instrument and its high sensitivity allows us to keep the exposure to radiation to a minimum, which is important for rare and valuable objects. “

In December last year, a small group from the Rijksmuseum in Amsterdam and the Queen Victoria Museum and Art Gallery (QVMAG) in Tasmania brought the Hartog Plate to the Synchrotron for scanning.

Image: (extract) X-ray fluorescence scan image showing elemental distribution of bismuth (red) lead (green) and germanium (blue). Entire picture here.

Prehistoric Iranian glass under synchrotron light

2018/01/242018/01/26

Scientists from University of Isfahan in Iran have analysed in the ALBA Synchrotron how were made ancient Iranian glass objects that date back to 2.500 BC. These decorative glass pieces were excavated from the ziggurat of Chogha-Zanbil, a type of stepped pyramidal monument, inscribed on the UNESCO World Heritage List.

Ziggurats, the most distinct architectural feature of the Mesopotamian, are a type of massive stone structure built thousand years ago as a temple where deities lived. Nevertheless, Chogha-Zanbil, near Susa (Iran), is one of the few existent ziggurats found outside the Mesopotamian area. During ancient times Chogha-Zanbil was known as Dur Untaš, and may had been a sacred city of the Elamite Kingdom, an ancient Pre-Iranian civilization centred in the far West and Southwest of what is now modern-day Iran.

In order to determine the chemical composition of these unique samples, including one piece of ceramics and one piece of metallurgical crucible, a team of Iranian scientists came to ALBA Synchrotron to analyse them using X-Rays Powder Diffraction at the MSPD beamline. The MSPD analyses were carried out on more than 100 points on the glass objects. Synchrotron light enabled them to obtain high resolution diffraction patterns, from whose interpretation researchers have deduced the exact composition of the clay based structure as well as glassy part of the samples.

>Read more on the ALBA website

Image: The glass objects were originally used at the walls and doors of the tempel Chogha-Zanbil.
Credit: Mohammadamin Emami