Snowflake - a snow or ice crystal, most often in the form of a six-beam at the ends of asterisks or hexagonal plates. Unicode has several snowflake characters: (U + 2744), (U + 2745), (U + 2746)
During very severe frosts (at temperatures below -30 ° C), ice crystals fall out in the form of “diamond dust” - in this case, a layer of very fluffy snow consisting of thin ice needles forms on the surface of the earth. Usually, in the process of its movement inside an ice cloud, ice crystals grow due to the direct transition of water vapor into a solid phase. How exactly this growth occurs depends on external conditions, in particular on temperature and air humidity. Scientists have identified the nature of dependence in general terms, but have not yet been able to explain it. Under some conditions, ice hexagons grow intensively along their axis, and then elongated snowflakes are formed - snowflakes-columns, snowflakes-needles. Under other conditions, hexagons grow mainly in directions perpendicular to their axis, and then snowflakes form in the form of hexagonal plates or hexagonal stars. A drop of water may freeze to a falling snowflake - as a result, irregularly shaped snowflakes form.
Closeup of snowflakes of Russian photographer Aleksey Klyatov.