Bismuth White (Bismuth Oxychloride) and Its Use in Portrait Miniatures Painted by George Engleheart

Abstract

This article documents the discovery of ‘bismuth white’ on three late eighteenth-century portrait miniatures in the Victoria and Albert Museum collections, painted by renowned English artist George Engleheart. Metallic bismuth and bismuth-containing minerals have been known for centuries and were used on various types of artistic production, from German Wismutmalerei to medieval manuscripts and Renaissance paintings. However, until now they had never been documented on portrait miniatures, despite documentary evidence that suggests their use. The Raman analysis of the three miniatures shows that bismuth oxychloride (BiOCl, corresponding to the mineral bismoclite) is present, and XRF data prove that this material was used as a white pigment in its own right. This work is a pilot study: it represents the first step in the rediscovery of bismuth white as an artist’s pigment, and hopes to provide encouragement to other institutions to look deeper in their collections and map out the use of a relatively rare white material which until now had not been detected or documented in fine art objects.