1) Inorganic pigment 
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 of cobalt oxide 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...
impure cobalt oxide
Zaffre is a crude oxide of cobalt obtained by heating cobalt ore in a current of air. It was used to prepare smalt and to stain glass blue during Victorian times.