Secret powder of pharaohs emits infrared radiation

Scientists were interested in the persistence of the Egyptian blue, still covering the ancient sarcophagi and the walls of the tombs, and found out that this pigment emits near-infrared radiation under certain illumination.

Recent studies have shown that the Egyptian blue paint, created 5250 years ago, can be used as a powder for fingerprints where conventional means are powerless.

This property of paint can be useful for conducting forensic examination. Arriving at the crime scene, forensic experts usually apply a powder of contrasting color to the objects, which sticks to the fingerprints left there. But prints are difficult to remove from glossy or embossed surfaces.

In such cases the Egyptian blue can be useful. The dye is applied in the same way as a conventional powder, but then the surface is illuminated and photographed with a camera that is equipped with a filter sensitive to near-infrared radiation. If there are prints, they will be clearly visible in the picture.