Happy New Year!!
Above is a micrograph of a pair of ornate snow crystals that likely fell within minutes of each other during the same snowstorm.
Image from The Schwerdtfeger Library
They’re part of the Wilson Bentley (1865-1931) snow crystal collection of the Schwerdtfeger Library. These hexagonal plate crystals (classified as P1a in the Lee/Magono snow crystal classification system) look the same but are far from being identical. The familiar six-sided shape of snow crystals (six-fold symmetry) results directly from the six-fold symmetry of the ice crystal lattice. But because even two crystals falling to the ground almost side-by-side fall through ever-so-slightly different environments, they won’t look identical, at least not when viewed through a microscope. Summary Author: Jim Foster