The Six-Fold Nature of Snow

If you could zoom in about a million times into any region of a snow crystal, such as the branch tip in figure 1below, you would see a lattice of hexagonal rings, as sketched in. So, at least in this ‘natural’ form of ice, the shape of the water molecule produces forces that link the molecules into a lattice of hexagonal rings. Wilson Bentley, the farmer-scientist who obtained the first photomicrographs of snow crystals, thought the forces were electromagnetic and in 1910 proposed an electromagnetic water model to help explain the six-cornered nature of ice.

Source: www.storyofsnow.com