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Updated: Jul 15, 2026
X-ray Powder Diffraction in Conservation Science: Towards Routine Crystal Structure Determination of Corrosion Products on Heritage Art Objects
Published on: June 8, 2016
Unravelling the spatial dependency of the complex solid-state chemistry of Pb in a paint micro-sample from
Stephen W T Price1, Annelies Van Loon, Katrien Keune
1Finden Ltd, Merchant House, 5 East St Helen Street, Abingdon, Oxfordshire OX14 5EG, UK. stephen@finden.co.uk.
Abstract:
The surface of many Old Master paintings has been affected by the appearance of whitish lead-rich deposits, which are often difficult to fully characterise, thereby hindering conservation. A paint micro-sample from Rembrandt's Homer was imaged using X-ray Diffraction Computed Tomography (XRD-CT) in order to understand the evolving solid-state Pb chemistry from the painting surface and beneath. The surface crust was identified as a complex mixture of lead sulfates. From the S : Pb ratios throughout the paint layer, we can conclude that S is from an external source in the form of SO2, and that the nature of Pb-SO4 product is dependent on the degree of diffusion/absorption of SO2 into the paint layers.
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