Azurite

(Cendree, Mountain blue, Copper blue, Ongaro, Azure Biadetti of Spain, Azure of the Magna)

azurite

Origin, History and Characteristics

Latin borrowed a Persian word for blue, labored, which in the form of lazurium became azurium, and gave us our word azure. Azurite is composed of a basic carbonate of copper, found in many parts of the world in the upper oxidized portions of copper ore deposits. Azurite mineral is usually associated in nature with malachite, the green basic carbonate of copper that is far more abundant. Azurite was the most important blue pigment in European painting throughout the middle ages and Renaissance by contrast, despite the more exotic and costly ultramarine having received greater acclaim. Azurite—then commonly called azzuro d'Alemagna—was often used for draperies, particularly in works by Duccio and his circle.

azurite
Powdered azurite

To prepare a color from it, lump azurite is ground into a powder, and sieved. Coarsely ground azurite produces dark blue, and fine grinding produces a lighter tone; however if not ground fine enough, it is too sandy and gritty to be used as a pigment. The medieval system included washing it to remove any mud and then separating the different grains by some process of levigation. If plain water is used it is a slow, laborious process, so they used solutions of soap, gum and lye. When azurite is washed, the very fine particles are rather pale, greenish sky-blue, and not much admired for painting. The best grades of azurite for painting were coarse: not sandy, but so course that it could be quite laborious to lay them on.

A Lady with a Squirrel and a Starling, Hans Holbein the YoungerA Lady with a Squirrel and a Starling (Anne Lovell?)
Hans Holbein the Younger
c. 1526-8
Oil on oak, 56 x 38.8 cm.
National Gallery, London

The background of Holbein’s portrait, which is particularly well preserved, reveals the strong greenish tone of azurite. The background was painted with two separate layers of grainy azurite, the most colorful variation of the pigment, mixed with lead white. The pigments were bound by linsead oil.

Glue size was often used as a binder to hold the pigment grains firmly in place. It was necessary to apply several coats of azurite to produce a solid blue, but the result was quite beautiful. The actual thickness of the crust of blue added to the richness of the effect, and each tiny grain of the powdered crystalline mineral sparkled like a minute sapphire, especially before it was varnished. Due to the coarseness of azurite, it was difficult to use in detail.

Azurite in Vermeer's Painting

In the Officer and Laughing Girl, azurite is found under a layer of natural ultramarine mixed with lead-tin yellow and traces of lead white in the area corresponding to the shadowed area of the green table clothe. Azurite was also detected in some of the light gray areas of Maid Asleep (see right) .Azurite is also found mixed with lead-tin yellow in the window green shutters of the Little Street (see right.).

Vermeer seems to have used azurite in light grays and mixtures of green where the brilliance of ultramarine would not have been appreciable. Like other painters of the time, Vermeer may have used azurite as a base color on which the far more costly natural ultramarine was painter over, for economical reasons.