Titre du document / Document title

Characterization of pararealgar and other light-induced transformation products from realgar by Raman microspectroscopy

Auteur(s) / Author(s)

TRENTELMAN K. ⁽¹⁾ ; STODULSKI L. ⁽¹⁾ ; PAVLOSKY M. ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ The Detroit Institute of Arts, Conservation Services Laboratory, 5200 Woodward Avenue, Detroit, Michigan 48202, ETATS-UNIS

Résumé / Abstract

Naturally occurring arsenic sulfide minerals are brightly colored and consequently have been used as artists' pigments since ancient times. Orpiment, As₂S₃, is yellow and is often found associated with realgar, As₄S₄, which is red to red-orange. When exposed to sunlight, unprotected realgar develops a surface coating of friable yellow material that, until recently, had generally been assumed to be orpiment. However, it has been determined that this material is pararealgar, a light-induced polymorph of realgar. We have identified pararealgar in a major work by the Renaissance master, Tintoretto. The accurate identification of pigments in artistic and historic works is of great importance for determining the construction, history, and future preservation of these works. We report here the characterization by Raman microspectroscopy of pararealgar and the various intermediate species involved in the light-induced transformation of realgar to pararealgar. The relative merits of Raman microspectroscopy and X-ray diffraction for the accurate and efficient characterization of these arsenic sulfide compounds are discussed.

Revue / Journal Title

Analytical chemistry   ISSN 0003-2700   CODEN ANCHAM 

Source / Source

1996, vol. 68, n^o10, pp. 1755-1761 (36 ref.)

Langue / Language

Anglais

Editeur / Publisher

American Chemical Society, Washington, DC, ETATS-UNIS  (1947) (Revue)

Mots-clés anglais / English Keywords

Chemical analysis ; Microanalysis ; Raman spectrometry ; Degradation product ; Photochemical degradation ; Inorganic pigment ; Polymorphism ; Cultural artefact ; Arsenic Sulfides ;

Mots-clés français / French Keywords

Analyse chimique ; Microanalyse ; Spectrométrie Raman ; Produit dégradation ; Dégradation photochimique ; Pigment minéral ; Polymorphisme ; Oeuvre art ; Arsenic Sulfure ; As2S3 ; As4S4 ; As S ;

Mots-clés espagnols / Spanish Keywords

Análisis químico ; Microanálisis ; Espectrometría Raman ; Producto degradación ; Degradación fotoquímica ; Pigmento inorgánico ; Polimorfismo ; Obra arte ; Arsénico Sulfuro ;

Localisation / Location

INIST-CNRS, Cote INIST : 120 B, 35400004334737.0130