/ ree • al • gar / Realgar	Jump to pigmentMadder lake (alizarine)AzuriteBone blackBrown ochreCarmineCadmium orangecadmium yellowCerulean BlueCalcium carbonate whitesCharcoalcobalt blueCobalt greencobalt violetCobalt yellowChrome orangechrome yellowcopper resinateEgyptian blueEmerald greenGreen earthIndian yellowIndigolead whiteLemon yellowmalachiteNaples yellowOrpimentlead tin yellowPrussian bluerealgarred leadRed ochresmalttitanium dioxideUltramarineUmbraVan Dyke brownverdigrisvermilionviridianYellow ochrezinc white

1.  Overview     2. History of use     3. Making the pigment     4. Technical details

About the chemical structure:          Chemical name: Red arsenic sulfide Formula: As2S3 Crystal system: Monoclinic - Prismatic (at Mineralogy Database) Refractive index: alpha = 2.4; beta = 2.81; gamma =3.02

How can you identify Realgar?          Chemical identification: n/a Spectra: Raman (at University College London), (pdf file download; at University of Florence, Italy) UV/VIS/IR-Spectra (at SpecLib, NASA)   Usage and handling:          Permanence: Toxicity: very good Realgar is very toxic (MSDS at Fisher Scientific)   Literature:             Wallert, A. Orpiment und Realgar, Maltechnik-Restauro, 90, 1984, p. 45 Artists’ Pigments. A Handbook of Their History and Characteristics, Vol. 3: E.W. Fitzhugh (Ed) Oxford University Press 1997, p. 47-79 Trentelman, K., L. Stodulski, and M. Pavlosky, Characterization of pararealgar and other light-induced transformation products from realgar by Raman microspectroscopy. Analytical Chemistry 68, 1996, p.1755-1761.

Other reds         (intro) - Madder lake (alizarine) - realgar - red lead - Red ochre - vermilion