Lapis Lazuli Used as a Pigment
High-quality lapis lazuli has been used as a mineral pigment for over 1,000 years. Bright blue pieces of lapis are trimmed of impurities and ground to a fine powder; the powder can then be mixed with oil or another vehicle for use as a paint.
Higher-grade pigments can be produced by washing the powder with mild acid to remove calcite and dolomite that dilute the blue color. The material is then processed to remove grains of pyrite and other foreign minerals. This lapis-derived pigment was named “ultramarine blue,” a name that has been subsequently used for hundreds of years.
During the Renaissance and into the 1800s, paintings done with ultramarine blue were considered to be a luxury because of their high cost. High-quality lapis lazuli was mined in Afghanistan and transported to Europe to manufacture ultramarine blue. This costly pigment was normally used by only the most accomplished artists and those who had wealthy clients to support the additional expense.
Ultramarine blue made from lapis lazuli is one of the few natural pigments with a permanent and vivid blue color, good opacity, and high stability. It has always been very expensive and today can sell for over $1,000 per pound.
Starting in the mid-1800s, artists and chemists began developing synthetic blue pigments for use as alternatives to ultramarine blue made from lapis lazuli. Some of these pigments also bear the name “ultramarine.” An artist who wants an ultramarine pigment made from lapis lazuli today must be sure that the pigment is not synthetic and is actually made from lapis lazuli. Synthetic ultramarine pigments have their advantages. Their blue color is usually deeper and more consistent than traditional ultramarine, and they also cost far less.
Today, because of cost, very little ultramarine made from lapis lazuli is used, mainly by artists who are striving to learn historical techniques or achieve results similar to master
painters of the past. It is prepared by a few pigment manufacturers who continue to use lapis lazuli from the historical sources in Afghanistan.