Turnbull's blue
Revision as of 07:18, 24 July 2013 by (username removed)
Description
An inorganic blue pigment. Turnbull's blue is a complex ferric ferricyanide that is produced by reacting a ferrous salt with potassium ferricyanide. It is made as an intermediate in the production of Prussian blue, but is not the same compound. Turnbull's blue is not used as a paint pigment but it is used in making blueprints. Blueprint paper is sensitized with ferric ammonium citrate and potassium ferricyanide. When the paper is exposed to light, the ferric ions are reduced to ferrous ions (Lewis 1993)..