Chemistry in ancient times: The development of blue and purple pigments

Abstract

Out of the Blue: The noble colors blue and purple were highly regarded in the past because of their rarity. Thus ancient civilizations invented blue and purple pigments, such as, Egyptian Blue (see amulet shown), Chinese Blue, and Chinese Purple, all of which contain alkaline-earth metals and copper. It is shown how their synthesis may have been developed in ancient times: an understanding of stoichiometry, the control of reaction temperature, and the hypothesis of knowledge transfer are essential.