egyptian blue

Egyptian blue, also known as calcium copper silicate (CaCuSi4O10 or CaOCuO(SiO2)4 (calcium copper tetrasilicate)) or cuprorivaite, is a pigment that was used in Ancient Egypt for thousands of years. It is considered to be the first synthetic pigment. It was known to the Romans by the name caeruleum. After the Roman era, Egyptian blue fell...