Pararealgar

Description

An orange-yellow arsenic sulfide mineral that can occur as a light induced alteration product of realgar. Pararealgar has been found in association with realgar in occasional classical and European paintings.

Synonyms and Related Terms

arsenic sulfide

Other Properties

Monoclinic, yellow, prismatic crystals. Fracture=brittle and uneven Luster=vitreous to resinous. Pigment particles are irregular with high relief.

Composition	AsS
Mohs Hardness	1.0-1.5
Density	3.52
Molecular Weight	106.99
Refractive Index	>2.02

Hazards and Safety

Highly toxic by ingestion and inhalation. Carcinogen and mutagen

Additional Information

° K. Trentelman, L. Stodulski, M. Pavlosky, 'Characterization of pararealgar and other light-induced transformation products from realgar by Raman microspectroscopy' Analytical Chemistry 68 (1996) 1755-1761.° Webmineral: Pararealgar

Authority

• Nicholas Eastaugh, Valentine Walsh, Tracey Chaplin, Ruth Siddall, Pigment Compendium, Elsevier Butterworth-Heinemann, Oxford, 2004