Ultramarine is famous for having been the most expensive pigment. It was more expensive than gold during the Renaissance. First used in 6th century Afghanistan, the pigment found its most extensive use in 14th and 15th century illuminated manuscripts and Italian panel paintings, often reserved for the cloaks of Christ and the Virgin. It's use as a pigment among ancient mediterranean cultures is very rare. It was imported to Europe by way of Venice.
Raphael, Chapel of Saint Severo, 1505, Perugia, Italy Left, visible image. Right IRFC image. The blue sky shows up in red in the IRFC image being ultramarine.
Cennini: Ultramarine Blue- Beautiful, illustrious and the most perfect beyond all other colors. Nothing surpasses its quality. Pay close attention to how its made and you will gain great honor and service from it. Get some Lapis Lazuli- chose that which has the richest blue color, the least ashy is the best. Confirm it is not azurite stone, which will be pleasing the eye. Pound it on a bronze mortar, covered up to contain the dust. After you have it all ready, get six ounces of pine rosin from the druggists, three ounces of gum mastic, and three ounces of new wax for each pound of lapis lazuli. Melt all together, then strain into a washbasin....Before you take the blue out of the porringer, but after it is quite dry of the lye, put a little of this kermes and brazil on it; and stir it all up well with your finger; and let it stand until it dries, without sun, fire, or wind. When you find that it is dry, put it in leather, or in a purse, and leave it alone, for it is good and perfect. And keep it for yourself, for it is an unusual ability to know how to make it properly. and know that making it is an occupation for pretty girls rather than for men; for they are always home, and reliable, and they have more dainty hands. Just be aware of old women.
Microscopic appearance at x500 mag. Left, artificial, right, mineral ultramarine.