Egyptian blue
| Egyptian blue | |
|---|---|
| Color coordinates | |
| Hex triplet | #1034A6 |
| sRGBB (r, g, b) | (16, 52, 166) |
| HSV (h, s, v) | (226°, 90%, 65%) |
| CIELChuv (L, C, h) | (28, 82, 263°) |
| Source | [Unsourced] |
| ISCC–NBS descriptor | Vivid blue |
| B: Normalized to [0–255] (byte) | |
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.
Egyptian blue is produced from a mixture of silica, lime, copper, and an alkali. Its color is due to a calcium-copper tetrasilicate CaCuSi4O10 of the same composition as the naturally occurring mineral cuprorivaite. It was first synthesized in Egypt during the Fourth Dynasty and used extensively until the end of the Roman period in Europe, after which its use declined significantly.
Apart from Egypt, it has also been found in the Near East, the Eastern Mediterranean, and the limits of the Roman Empire. It is unclear whether the pigment's existence elsewhere was a result of parallel invention or evidence of the technology's spread from Egypt to those areas.
After the Roman era, Egyptian blue fell out of use and, thereafter, the manner of its creation was forgotten. In modern times, scientists have been able to analyze its chemistry and reconstruct how to make it.