Cobalt blue
German: Kobaltblau.
English: Cobalt blue.
Chemistry: Cobalt(II) oxide-aluminium oxide, or cobalt(II) aluminate, CoAl2O4; made by sintering cobalt(II) oxide with alumina at 1200 °C; Cobalt blue is lighter and less intense than Prussian blue; it is extremely stable.
Use: blue pigment; coloring in ceramics, Chinese porcelain, jewelry, paint.
Cobalt glassName: Smalt.
Chemistry: a very intense pigment, deep blue, colored glass; prepared by including a cobalt compound, typically cobalt oxide or cobalt carbonate, in a glass melt. Cobalt is a very glass colorant and very little is required to show a noticeable amount of color; optical filter for yellow, expanding to see violet and blue hues.