Ultramarine and the Purification of Lapis Lazuli

A lecture by Spike Bucklow

This talk will consider the cultural significance of the artists’ pigment, natural ultramarine. The talk will indicate why ultramarine was the most expensive pigment on the painter’s palette, often equal in price to gold.

It will start with the exotic geographic origin of ultramarine’s raw material, the mineral lapis lazuli. It will then consider the numerous uses of lapis lazuli outside the artists’ workshop that help account for its economic and metaphysical value. It will then acknowledge the geological composition of lapis lazuli and the process of purification that converted it into the painters’ finest blue colour. The process has been documented in numerous recipes that span a thousand years and can be consistently interpreted in terms of Aristotle’s four element theory. The purification is labour intensive and requires skill and patience and would have been a formative part of many medieval artists’ training. The elemental composition and metaphysical significance of natural ultramarine embodied cultural meaning in the blue pigment which imparted an important, and once widely recognized but now mainly lost, material dimension to visual art.

The talk will be illustrated with historic documents and works of art and is based upon a chapter in the book The Alchemy of Paint.