Different Categories of Classifications and Shapes of Snowflakes

We were taught that no two snowflakes are the same.  In fact there are 39 different categories of snowflakes out there with different shapes.
The number of categories snow crystals can be categorised into has been steadily increasing over the years. In early studies in the 1930s, they were classified into 21 different shape-based categories; in the 1950s, this was expanded into 42 categories, in the 1960s to 80 categories, and most recently in 2013 to a staggering 121 categories.

This latest study splits the classification into three sub-levels: general, intermediate, and elementary. The graphic featured here shows the 39 intermediate categories, which themselves can be grouped into 8 general categorisations. Each of the intermediate categories  have specific characteristics, which are detailed at length in the research paper this graphic is based on.
The eight intermediate categories shown in the graphic are:
  • Column crystals.
  • Plane crystals.
  • Combination of column & plane crystals.
  • Aggregation of snow crystals.
  • Rimed snow crystals.
  • Germs of ice crystals.
  • Irregular snow particles.
  • Other solid precipitation.