Note 1466 — ULTRAMARINE.

Of azur there are two sorts, one called by painters azurro oltramarino, and the other azurro dell’ Alemagna. The ultramarine is that made of the stone known by the name of lapis lazuli, which is the proper matrix of gold ore. This stone, after being pounded and washed, is reduced to an impalpable powder. It is then brought back to its lively and beautiful colour by means of a certain paste composed with gum, and is refined and freed from all moisture. This kind is that most esteemed; and according to its colour and fineness is purchased at a high price by painters; for it not only adds great beauty to paintings, but it withstands fire and water—two powers which other colours are not able to resist.—Pirotechnia, p. 38. The German azur of Biringoccio is not smalt; for he describes that colour before under the name of zaffera.

See also Fallopius, who in 1557 wrote his book De Metallis seu Fossilibus, chap, xxxiii. p. 338, who observes that ultramarine was then selling for 100 golden scudi per ounce.