Identification of Vivianite in Painted Works of Art and Its Significance for Provenance and Authorship Studies

Abstract

Vivianite ( F e 3 ( PO 4 ) 2 ·8 H 2 O ) is a rare blue historical pigment, which can be profitably used in authorship ascription or copy identification. However, its tendency to degrade complicates its proper identification in paint layers. Reference vivianite mineralogical samples were analysed in order to compare and to test the limits of structural analyses on possibly degraded vivianite samples ( X ‐ray diffraction and vibrational spectroscopies). The same methods, in their μ‐configuration, were tested on micro‐samples of the paintings and their limits evaluated. A sedimentary origin of the pigment has been suggested. Vivianite was detected in various works by J ean G eorge de H amilton (1672–1737) and in a L ate G othic T ransylvanian altarpiece.