Silver iodide is often used for artificial snowfall. Silver iodide is a yellow chemical crystal, which is usually used as a photosensitizer in photographic materials. The crystal of silver iodide is very similar to the hexagonal monomer size of snow crystal, and the atomic arrangement in their monomers is also very similar, and the lattice spacing between them is also very close (silver iodide is 4.58 angstroms, and snow crystal is 4.52 angstroms).