Cobalt glass is a deep blue colored prepared by adding compounds to the molten glass. It is appreciated for its attractive color. It is also used as an optical in to filter out the yellow flame caused by the contamination of , and expand the ability to see violet and blue hues. Under light, cobalt glass has twice the effect.Moncler Online 

Some people collect objects made from cobalt glass, amassing large collections. One popular example of cobalt glass is , as in the distinctive blue bottles of sherry.

[] For pigment use

Powdered cobalt glass, called smalt (or also simply cobalt glass), has been historically important as a in painting, pottery, for surface decoration of other types of glass and ceramics, and other media. It is colored to a deep hue using ions derived from cobalt oxide. Cobalt aluminate can be used in a similar way, and is now more common, often known as "".Cobalt glass and smalt are made from and are not the same as cobalt blue, which is colored by cobalt ion is a similar way, but using a melting process with .Moncler Salg 

[] History

The earliest known example of cobalt aluminate glass dates to a lump from about 2000BC in , very possibly intended for use as a pigment; it is then rare until the modern era. About five centuries later cobalt oxide smalt appears as a pigment in Egyptian pottery, and soon after in the region, and this is the pigment normally known as smalt. In paintings, smalt has a tendency to lose its colour over a long period and is little used today. However used in ceramics for decoration it keeps its colour well, and is the main blue used in blue and white pottery from a wide range of dates and areas, including Chinese from the and , Renaissance Italian and .salg Moncler ned Vest Herre

used smalt glazes from the onwards, though Chinese cobalt glass is found from the (1122-221 BC). Cobalt was used as a pigment in from the 13th century. A fragment of a mud painting in the ancient city of has been found to contain smalt, judged to be dated between 11th to 13th century. A large quantity of smalt was purchased for the decoration of the gallery of at in 1536. Smalt, normally now discoloured, is common in European paintings from the 15th to 17th centuries. for example, it was found in Hans Holbein the Younger's portrait of Sir William Butts (ca. 1540), in Michael Pacher's painting "The Early Fathers' Altar" (ca. 1483), and in the frescos of Domenico Ghirlandaio (1449–1494).Billige Moncler ned jakker mnd 

The invention of a European smalt process is sometimes credited to a named , around 1540-1560 The process used for producing cobalt smalt glass at the industrial manufacturing center in Norway in the 19th century has been documented as smelting cobalt oxide together with quartz and potassium carbonate. The result was an intensive blue glass-like substance that was ground and sold to producers of glassware and porcelain.Moncler Jakker