Dust

Dust in Philip Pullman's trilogy of novels His Dark Materials is a fictional form of dark matter, an elementary particle that is of fundamental importance to the novels. Dust is invisible to the human eye and cannot be seen without the use of special instruments such as the amber spyglass or a special film. However, while humans cannot see dust without the use of outside devices, creatures such as the mulefa are able to see dust with their own eyes. Unlike ordinary particles, Dust is conscious... full article at wikipedia