The science of snowflake shapes
You might have heard the saying "No two snowflakes are exactly the same." This is actually a true statement. Snowflakes all look different, but can be categorized into the 35 separate categories. In the beginning of their formation process, they all start as the same six-sided Basal Facet, which is known as their originally shaped ice crystal. From there, they grow!
All snowflakes start from two ingredients, water vapor and dust.
Water vapor freezes onto dust particles in the upper atmosphere forming the original six-sided ice crystal.
From here, depending on the exact temperature and humidity, branches will begin to form off of each of the six sides of the original ice crystal. Water vapor continues to freeze on each of these branches in different orders and patterns.
Eventually, these snowflakes become too heavy and fall from their cloud back to the surface of the earth as long as temperatures remain at or below freezing.