Very rare ( later electrified ) glass lamp in the shape of a lantern in blue cobalt-colored glass decorated with a cut pattern most likely from the end of the 19 century. Based on the brass ring and the shape of the bottom of the glass, we expect it to come from England, as other lamps with the same ring pattern and bottom glass pattern always are described as being English. It is most likely colored with cobalt oxide-aluminum oxide. The very costly and extraordinarily stable pigment of pure blue color was discovered by Thenard in 1802. It is now the most important of the cobalt pigments. Although smalt, a pigment made from cobalt blue glass has been known at least since the Middle Ages, the cobalt blue established in the nineteenth century was a greatly improved one. Cobalt blue in impure form had long been used in Chinese porcelain but was independently discovered as a pure alumina-based pigment by Louis Jacques Thenard, in 1802. Commercial production began in France in 1807. The first recorded use of cobalt blue as a color name in English was in 1777.