Lapis Lazuli and Ultramarine: A Short Guide to the World's Most Precious Blue

For most of history, a truly deep, clear blue was one of the hardest colours to make and one of the most expensive to buy. The pigment behind it, ultramarine, came from a single stone: lapis lazuli. Its story explains why blue still carries such a sense of value today.

The stone

Lapis lazuli is a rock rather than a single mineral. Its blue comes mainly from lazurite, and it is often flecked with golden pyrite and streaks of white calcite. The most celebrated deposits are in the mountains of Badakhshan in north-east Afghanistan, which have been mined for thousands of years. Lapis was carved into jewellery, seals and inlay long before anyone ground it into paint.

From stone to pigment

Simply crushing lapis gives a disappointing greyish blue, because the lazurite is mixed with other minerals. The breakthrough was a method of extracting it: the ground stone was kneaded into a dough of wax, resins and oils, then worked in a mild alkaline solution so that the blue particles washed out and the impurities stayed behind. The first extraction gave the richest blue; later washes produced paler grades, sometimes called ultramarine ash.

The name itself means "beyond the sea", a reminder that the pigment reached Europe from far away. In Renaissance Italy it could cost more than gold, and contracts for paintings sometimes specified exactly how much ultramarine was to be used, often for the robes of the Virgin Mary.

Natural versus synthetic ultramarine

In the 1820s, a competition in France prompted the development of a synthetic ultramarine, made from widely available materials such as kaolin, soda, sulphur and charcoal. Often sold as French ultramarine, it is chemically very similar to the natural pigment, far cheaper and more consistent from batch to batch.

So why does anyone still use the real thing? Natural ultramarine tends to have a softer, more complex quality, with tiny variations in particle size and the occasional glint of mineral. Synthetic ultramarine is more uniform and intensely saturated. Neither is better in every case; they suit different work.

• Natural ultramarine: fine art, icon and manuscript work, restoration where historical accuracy matters, and special decorative commissions.
• Synthetic ultramarine: larger-scale decorative painting, paint and plaster making, and any project where consistency and cost matter most.

Working with ultramarine

• Ultramarine is sensitive to acids, so it is not a good choice where it may come into contact with acidic materials.
• Grade and particle size change the colour noticeably. Always test a sample in the binder you plan to use, whether that is oil, egg tempera, lime or a modern acrylic medium.
• Handle dry pigments carefully. Avoid breathing in fine powder and follow the supplier's safety data sheet.

What to ask when sourcing blue pigment

• Is it natural or synthetic, and from which source?
• What grade is it, and how pure?
• Is the colour consistent between batches, and can a sample be retained for reference?
• How much do you need, and over what timescale?

Sourcing pigment with us

We source natural and specialist pigments for artists, decorators, restorers and designers, and arrange samples so you can test before ordering. Explore our pigment collection or tell us what you need.