This is a hands-on demonstration. Try it and see, if you're lucky enough to have snow! As noted in the problem, you should observe that the crystalline structure of ice is hexagonal (it is said to have six-fold symmetry). More specifically, "Ice Ih" is the phase of ice that has hexagonal crystal structure, and almost all the atmospheric ice you're likely to encounter is ice Ih. As a consequence, many snowflakes also have six-fold symmetry, as you can observe.