Egyptian blue

Egyptian blue, also known as copper calcium silicate (CaCuSi4O10 or CaOCuO(SiO2)4 (copper calcium tetrasilicate)) or cuprorivaite, is a pigment used in ancient Egypt for thousands of years. It is considered the first synthetic pigment. It was known to the Romans as Caeruleum. After Roman times, Egyptian blue fell into disuse, and subsequently the way it was made fell into oblivion. In modern times, scientists have been able to analyze their chemistry and piece together how to do it. The ancient Egyptian word wꜣḏ means blue, blue-green and green. The first recorded use of “Egyptian Blue” as a color name in English was in 1809.