Definition of "zaffer" []

• An impure oxide of cobalt, used to produce a blue color in enamel and in the making of smalt. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The search for native cobalt, especially outside of Saxony or the Erzgebirge, was tied to the development of zaffer and smalt industries — refined versions of cobalt used by painters and in vitreous colormaking — and to recognition of the quality of the cobalt-based colors."
• "This caused the liquid to harden and, according to Peckitt, it also extracted harmful salts. reference The zaffer-niter compound was dried and powdered: a quantity of this mixture was added to a crucible (“pot”) of molten glass to create the desired blue color. reference"
• "Instructions for creating zaffer blue, a color found on the plaque, called for firing the zaffer in a reverberating furnace for about twelve hours, followed by the addition of vinegar and by grinding and washing. reference This prepared zaffer was then mixed with the universal fondant and melted on a high heat."