Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by function]
6. colorant (material)
7. pigments
8. [pigment by color]
9. blue pigment
10. synthetic inorganic blue pigment

Anotations

Scope note:

A synthetic inorganic colorfast pigment having coarse, irregular particles and ranging in color from a powdery blue to a royal blue. It is composed of a double silicate of calcium and copper, prepared by heating a mixture of silica, copper salts, and calcite in a sodium carbonate flux, forming a stable blue frit. Egyptian blue is stable in all types of media and is unaffected by acids or alkali. It was used by the ancient Egyptians over 5000 years ago as a pottery glaze and watercolor pigment in wall paintings. Similar materials, later manufactured in Italy and called Pompeian blue and Pozzuoli blue, have similar chemical compositions and optical properties.