Ice crystal

[2] Depending on environmental temperature and humidity, ice crystals can develop from the initial hexagonal prism into many symmetric shapes.

[1] The symmetric shapes are due to depositional growth, which is when ice forms directly from water vapor in the atmosphere.

[5] Small spaces in atmospheric particles can also collect water, freeze, and form ice crystals.

When squeezed between two layers of graphene, water forms square ice crystals at room temperature.

[22][23] The aerospace industry is working to design a radar that can detect ice crystal environments to discern hazardous flight conditions.

Ice crystals can melt when they touch the surface of warm aircraft, and refreeze due to environmental conditions.

A close-up of growing ice crystals displaying typical hexagonal symmetry
An example of a hexagonal plate (top) and a hexagonal column (bottom), typical ice crystal shapes.
Further freezing of water on an ice crystal produces snowflakes .
A halo created by light reflecting off of ice crystals in cirrus clouds. This specific halo is called a 46° halo .
Dendritic ice crystals imaged with a scanning electron microscope . The colors are computer generated .