Why was this blue so precious?

Start with what you see

Lapis lazuli is a rock containing several minerals. Its blue comes mainly from lazurite. Making a useful pigment meant separating blue-rich material from unwanted components, then combining the pigment with a binder. Colour was also a problem of craft.

What is happening?

Natural ultramarine was made from lapis lazuli. Its preparation required more than simply crushing a rock, helping explain why painters treated the colour as precious.

A closer look

1. Select lapis lazuli

   Lazurite gives this rock its rich blue.

2. Prepare the pigment

   Processing separates the useful blue particles.

3. Mix and paint

   A binder turns pigment into usable paint.

Try a concrete example

A blue stone, a blue powder and blue paint are three different materials. Grinding changes particle size, but does not automatically remove the other minerals in the rock. Separating useful pigment and mixing it with a binder solve different problems. When looking at a painting, colour can therefore lead to questions about materials, preparation and technique. The appearance alone cannot tell you a pigment’s exact origin or establish what a particular painter paid for it.