This synthetic copper blue (copper and calcium carbonate) was previously made with swamp lime and copper lye. It is a lighter blue with a chemical composition similar to azurite.
- Chemical description: Basic Copper calcium carbonate
- ColorIndex: PB 30.77420
- Suitability: Tempera, Watercolor / Gouache
- Colors: Blue, Turquoise
- Forms: powder
- Solubility in water: insoluble