Synthetic Ultramarine Blue Pigment

Creating Synthetic Ultramarine Blue Pigment

To complete the pigment display, Lucy created a selection of synthetic ultramarine samples. She mixed silica, kaolin, charcoal, sulphur, potash & rosin and placed this mixture in a crucible in a kiln to chemically use the materials. (See diagram below for more details on the steps involved)

Materials

Synthetic Ultramarine & ultramarine pigment cakes 

Methodology 

To accompany the especially selected syn. ultramarine samples purchased from leading pigment retailers Kremer, L.Cornelissen & Son she wanted to create an intermediate material in the process, synthetic ultramarine pigment cakes. (see images below). Due to the variable conditions in the kiln & owing to the fact that these materials would then be re-ground & washed the cakes have a subtle variegated surface.

Ultramarine Pigment lining the inside of a crucible. 

Diagram explaining the main stages in synthetic ultramarine production. 

Workspace showing the combined materials before the first calcination and after. 

Ultramarine pigment cake & crucible. (first calcination)

Ultramarine Pigment cake crushed before being washed.

Ultramarine Pigment inside of a crucible. (second batch with different ratio of ingredients) 

Ultramarine Pigment inside of a crucible, second calcination. (Notice the grey dust settling on the pigment cake, this will be washed away.)