Color enhanced scanning electron microscope of ammonium nitrate (NH4 NO3) crystals. The crystals were dissolved in water and a few small drops of the solution were placed on a microscope coverslip and evaporated in a dessicator. The residue was coated with gold before being photographed. Ammonium nitrate is very hygroscopic and the original crystals "liquefied" at high relative humidity of the air but solidified as the humidity was severely reduced. This substance consists of gases (hydrogen, nitrogen, oxygen) and is used as an explosive. Because of its high nitrogen content (ammonia and nitrate) it is used as a fertilizer. Image width: 576 micrometers. Magnification: 173.5x if the image is printed 10 cm wide.