Triptych

Pigments (continued)

Ultramarine

An intense blue pigment formed after a lengthy extraction process from the mineral lazurite, a component of the semi-precious stone, lapis lazuli. The only known source of lapis lazuli in the 14th century were the quarries at Badakshan, located in north east Afghanistan.

The rarity of the source, the cost of transporting it for such a distance, and the small amount of pigment which was finally extracted from the mineral after crushing and purifying it, led to ultramarine costing even more than pure gold.

Azurite

A blue pigment with a slight greenish tinge obtained by grinding with water the mineral known as azurite, an ore of copper. Deposits of this mineral are found in Italy as well as other parts of Europe.

It was considerably less expensive than the pure blue ultramarine, and was therefore often used when a blue was required, despite a wide variation in its colour, its tendency to darken with age and its poor covering ability if the pigment was too finely ground.