Wednesday, September 1, 2010

Ultramarine, Part I

There is one natural blue pigment that is considered without peer: Ultramarine. A common color on European palettes by the Middle Ages, it is the color of the blue skies of the Renaissance, of Leonardo. Its name comes from the Italian oltramarino, "beyond the sea," as it had to be brought across the Mediterranean to Europe from the other side of the known world. Real ultramarine is made from the semi-precious stone Lapis lazuli, which is only available from a few locations around the globe.

The very best Lapis lazuli comes from the remote mountains of Badakhstan province, in northeastern Afghanistan. The Sar e Sang mine has been in operation for more than 6,000 years. The rock was probably first exported to Ancient Egypt. Marco Polo visited this mine in 1271, during his trip across Asia.

Lapis lazuli is a complex silicate rock, containing mostly lazurite but also calcite, sodalite, and pyrite. The highest grades are more intensely blue, and have smaller inclusions.

The gold speckles are pyrite (Fools' gold).

Lapis is a difficult material to mine. It is labor-intensive to grind and purify. These factors, along with the formidable remoteness of the mine and the rock's lengthy transport, made Ultramarine incredibly expensive. Worth more than gold, the high cost put it out of reach for many artists. It was often reserved for special subjects, such as the robes of the Virgin and Child. The asking price of a painting was often based merely on the quantity of ultamarine used.

The issue of cost was taken seriously enough that the French government offered a reward to anyone who could synthesize it cheaply. In 1828, Jean Baptiste Guimet won the prize. The synthetic ultramarine he developed quickly superseded its natural counterpart and is still in use today.

Real ultramarine is distinguishable from the synthetic variety by a less intense saturation. It has a glowing, gemlike quality stemming from its crystal structure. The effect is striking.

The painting, Bacchus and Ariadne, by Titian, serves as an example of how beautiful Ultramarine can be in the right hands. This painting was part of a series of restorations done in the late sixties. Its unveiling was controversial. The public did not associate the new colorful look with Titian, the sky in particular. Some critics suggested that this was the result of careless work by the restorers. I will not enter into this debate, but I will say that, having seen the real color, this may be what the painting looked like when it was new.

Given the high cost of finished pigment, I have decided to make my own Ultramarine from scratch. In the next installment, I will show how this was done.

No comments: