An interesting fact about Egyptian Blue. In the 19th century, Egyptian Blue was re-discovered. The excavations at Pompeii revealed that many wall paintings had Egyptian Blue on them, and this prompted scientists to investigate the exact composition of this pigment. Since then, researchers have gained a much deeper understanding of its unique properties. Experiments found that Egyptian Blue has the highly unusual quality of emitting infrared light when red light is shone onto it. This emission is extraordinarily powerful and long-lived, but cannot be seen by the naked eye, because human vision does not normally extend into the infrared range of the light spectrum. In addition, scientists unexpectedly discovered that Egyptian Blue will split into ‘nanosheets’ – a thousand times thinner than a human hair – if stirred in warm water for several days. Scientists now believe that its unique properties may make Egyptian Blue suitable for a variety of modern applications.