Cobalt glass

It is used in the distinctive blue bottles of Harvey's Bristol Cream sherry and Tŷ Nant mineral water.

The earliest known example of cobalt aluminate glass dates to a lump from about 2000 BC in ancient Mesopotamia, very possibly intended for use as a pigment; it was rare until the modern era.

A fragment of a mud painting in the ancient Tangut city of Khara-Khoto has been found to contain smalt, judged to be dated between the 11th and 13th centuries.

[12][13] The invention of a European smalt process has traditionally been credited to a Bohemian glassmaker named Christoph Schürer, around 1540–1560.

James VI and I considered awarding a patent for making a "blue azure" product for this purpose in Scotland in February 1609.

Cobalt glass for decoration
Regulation cobalt blue olive oil tasting glass with watch glass cover
Ming dish, with smalt blue decoration
Late Roman (circa 4th century AD) finger ring with blue glass intaglio of the figure of Victory
Samples of smalt in the Historical dye collection of the Technical University of Dresden, Germany