Do all snowflakes have unique shapes?
It is highly unlikely that you’ll find two identical snowflakes. Feel free to try to prove us wrong, but your search may involve some cold feet! If you compared 1 million snowflakes (a minuscule fraction of the flakes in a single snowstorm), performing two comparisons per second, you’d need about 100,000 years!
A simple snowflake is a single ice crystal, but most flakes are an aggregation of a group of ice crystals. Ice crystals are six-sided and come in four basic shapes: column, needle, hexagonal plate and dendrite. The shape in which an ice crystal grows depends on the air temperature around it. As a crystal moves through a cloud it continually encounters different temperatures, which continually modify its shape. Crystals also hit other crystals and break, chip or crack, further altering their shape.
You might be able to find two similar shapes of the initial crystals, but they will be hard to locate in the cloud. Maybe it’s better to just stand in a snowfall and enjoy their beauty rather than look for twins! Or view wonderful photos of ice crystals at The Bentley Collection.