/ vuh • rih • dee • uhn / Viridian	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: Chromium(III)-oxide dihydrate Formula: Cr2O3 · 2 H2O Crystal system: probably hexagonal Refractive index: alpha and beta = 1.62; gamma = 2.12

A swatch of Viridian paint:

How can you identify Viridian?          Chemical identification: It isdistinguished microscopically by its large particle size. Viridian's particles are slightly rounded and the pigment is insoluble and unchanged in chemical tests Spectra: Raman spectra (at University College London), (pdf file download; at University of Florence, Italy)   Usage and handling:          Permanence: Toxicity: very good MSDS (at Fisher Scientific)   Literature:             Artists’ Pigments. A Handbook of Their History and Characteristics, Vol. 3: E.W. Fitzhugh (Ed.) Oxford University Press 1997, p. 273 - 293

Other greens         (intro) - Cobalt green - copper resinate - Emerald green - Green earth - malachite       verdigris - viridian