Originating from the Persian word lazhuward meaning ‘blue’, and the Arabic word lazaward meaning ‘sky’, lapis lazuli is a rock composed primarily of the minerals lazurite, pyrite and calcite. Pyrite has a metallic lustre, whereas calcite and lazurite have sub-vitreous lustres. All three minerals are opaque. Lazurite gives lapis lazuli its characteristic and highly prized blue colour, pyrite appears as golden flecks, often referred to as ‘the stars in the sky’, and calcite is present as white veins running throughout the rock. The more calcite in the chemical composition, i.e. the whiter the rock, the less valuable it is.

The highest quality lapis lazuli is most commonly mined from Sar-e-Sang in the Badakhshan region of northern Afghanistan. It has been sourced there for over 6000 years, however nowadays lapis lazuli quarries can also be found in the banks of the Slyudyanka and Malaya Bystraya rivers, as well as Lake Baikal in Russia.

Due to its intense blue colour, lapis lazuli has been extensively used for aesthetic and decorative purposes since antiquity. For example, the ancient Egyptians used it to embellish sacred objects, and the Babylonians shaped it into beads for adornments.

Lapis Lazuli for Pigment

Lapis lazuli was also widely used in Medieval and Renaissance paintings as a deep blue pigment known as ultramarine. For example, it was used to paint the blue clothing in Ortolano’s Woman Taken in Adultery, which is displayed near to the case in The Courtauld Gallery.

In the celebrated craftsman’s handbook, Il Libro dell’Arte, Cennino Cennini (1360-1427) describes many different methods and techniques used in painting and decorating surfaces. Included in this manual is a detailed explanation of the long and arduous process required to prepare ultramarine pigment from rough lapis lazuli rock. A hue highly admired by Cennini, he begins, “ultramarine blue is a colour illustrious, beautiful, and most perfect, beyond all other colours; one could not say anything about it, or do anything with it, that its quality would not still surpass.”

A full version of this account, titled On the Character of Ultramarine Blue, and How to Make it, can be found here.