Zaffre, a pre-scientific substance (see List of alchemical substances), is a deep blue pigment obtained by roasting cobalt ore, and is made of either an impure form cobalt oxide[1] or impure cobalt arseniate. During the Victorian Era, zaffre was used to prepare smalt and stain glass blue.
The first recorded use of zaffre as a color name in English was sometime in the 1550s (exact year uncertain). [2]