Dust

Dust is a general name for minute solid particles (diameter less than 500 micrometers; otherwise see sand or granulates[?]), and in general, for finely divided matter.

On Earth, dust occurs in atmosphere from a number of sources : soil dust lifted up by wind , volcanic eruptions, human atmospheric pollution are only examples. Dust is also widely present in the space (see interstellar dust, Zodiacal light), where gas and dust cloud are primary precursors for planetary systems[?].

The dust which collects in homes is composed of the atmospheric dust combined with the dust from the human inhabitants, mostly from our own skin and the fibers of our clothing and coverings. It is removed with a cleaning cloth or vacuum cleaner.

Dust physical behaviour follows laws that are not comparable with that of solid or fluid matter. For example the pressure on a box full of dust needs not to be uniform. See physics of granulate matter[?] for explanation.

See also dust storm.