Snowflakes are endlessly fascinating and incredibly beautiful. But while they're all (sort of) unique, they can be neatly divided into well-defined types of flake. This chart shows them all.

Column crystals, plane crystals, irregularities, aggregates, germs... you probably never knew that snow flakes could take so many forms. Based on a research paper by Takao Kameda, this should be enough for you to talk more intelligently than ever about the white stuff this winter. [Compound Interest]