English: The dust, consisting of micro crystals of corundum (ruby) - an interesting by-product of mechanical production. It is formed during grinding operations, if production using alumina grinding wheels. Then he picked up a ventilation system and accumulates outside of the shops. Visually it looks like gray-pink sand with very significant corundum brilliance, that immediately attracts attention. This series of four photos shows a gradual transition from the normal appearance of the dust as it accumulates in areas of emissions to macro photography of crystal from which the dust is.