If you look closely at snowflake shapes, you will see many different variations. Rarely are two snowflakes alike.
Have you ever considered how snow forms?
Snow begins as a tiny ice crystal or even a speck of dust. This moisture brings condensation and these drops or particles begin to stick together and form hexagonal crystals, sometimes in clumps, as they descend through warmer air.
Is every snowflake different?
It's improbable that you will ever find two snowflakes that are alike. The snowflake's hexagonal symmetry has its origin in the shape of a water molecule, which consists of an atom of oxygen and two atoms of hydrogen. They are connected in such a way that the hydrogen "arms" make an angle like the arms on the letter x. This angle ensures that when the water molecules link to form a crystal, the resultant symmetry will be hexagonal.
Regarding the probabilities of combination, a single snow crystal consists of something like one quintillion molecules of water. The number of ways that many molecules can be arranged into six-sided crystals is astronomical. So the odds are huge that no two snowflakes have ever been exactly alike.
Credit: Chris Burnett
"Ice Crystals in Montreal" taken January 18, 2013.
How many different types of snowflakes are there? Below are the more common snowflake shapes, courtesy of www.SnowCrystals.com.