Are you an EPFL student looking for a semester project?
Work with us on data science and visualisation projects, and deploy your project as an app on top of Graph Search.
Concept
Cobalt blue
Summary
Cobalt blue is a blue pigment made by sintering cobalt(II) oxide with aluminum(III) oxide (alumina) at 1200 °C. Chemically, cobalt blue pigment is cobalt(II) oxide-aluminium oxide, or cobalt(II) aluminate, CoAl2O4. Cobalt blue is lighter and less intense than the (iron-cyanide based) pigment Prussian blue. It is extremely stable and historically has been used as a coloring agent in ceramics (especially Chinese porcelain), jewelry, and paint. Transparent glasses are tinted with the silica-based cobalt pigment "smalt".
Cobalt blue in impure forms had long been used in Chinese porcelain. The first recorded use of cobalt blue as a color name in English was in 1777. It was independently discovered as a pure alumina-based pigment by Louis Jacques Thénard in 1802. Commercial production began in France in 1807. The leading world manufacturer of cobalt blue in the nineteenth century was Benjamin Wegner's Norwegian company Blaafarveværket ("blue colour works" in Dano-Norwegian). Germany also was famous for production of it, especially the blue colour works (Blaufarbenwerke) in the Ore Mountains of Saxony.
Cobalt glass is used decoratively, and also as an optical filter to remove or hide certain visible colors.
Art
Cobalt blue was the primary blue pigment used for centuries in Chinese blue and white porcelain, beginning in the late eighth or early ninth century.
Traditional Bolesławiec pottery from Poland also makes an extensive use of cobalt blue glaze. The pigment was used along with white in classic patterns of blue and white dots before the synthetic production of more variously-colored pigments (yielding such colors as green, red, orange).
Watercolorist John Varley suggested cobalt blue as a good substitution for ultramarine for painting skies, writing in his "List of Colours" from 1818: "Used as a substitute for ultramarine in its brightness of colour, and superior when used in skies and other objects, which require even tints; used occasionally in retrieving the brightness of those tints when too heavy, and for tints in drapery, etc.
Official source
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.