Silver iodide is an inorganic substance with the chemical formula of AgI. It is a bright yellow odorless microcrystalline powder with α and β Two types, α Type B is a cubic crystal, with a density of 6.010g/cm3, a melting point of 558 ℃, and a boiling point of 1506 ℃. β Type B is hexagonal crystal, with a density of 5.683g/cm3, which is converted to α Type. It is insoluble in dilute acid, water, slightly soluble in ammonia, and easily soluble in potassium iodide, potassium cyanide, sodium thiosulfate and methylamine. Whether silver iodide is solid or liquid, it has photosensitive characteristics, and can feel light from ultraviolet to about 480 mm wavelength.