Snowflake is a snow or ice crystal, most often in the form of a six-pointed starlet or hexagonal plates. In Unicode, there are several characters of the snowflake: (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 is formed on the surface of the earth. Usually in the course of its movement inside an ice cloud, ice crystals grow due to the direct transition of water vapor to the solid phase. How exactly this growth occurs depends on external conditions, in particular on the temperature and humidity of the air. The nature of the dependence of scientists in general terms revealed, but to explain it yet could not. Under certain conditions, ice hexahedrons grow along their axis, and then snowflakes of elongated shape are formed-snowflakes-columns, snowflakes-needles. In other conditions, hexahedrons grow mainly in directions perpendicular to their axis, and then snowflakes are formed in the form of hexagonal plates or hexagonal stars. To a falling snowflake, a drop of water can be frozen - as a result, snowflakes of irregular shape are formed.
A closeup of the snowflakes of the Russian photographer Alexei Klyatov.