Snow Crystal Classification translates Ukichiro Nakaya's 1954 morphology charts into a design system. In his Hokkaido laboratory, Nakaya sorted dendrites, plates, and columns across a temperature-versus-humidity grid, photographing each crystal under dark-field illumination.

Reflected light yields frosted white-cyan figures on a deep cold field, with a documented blue cast for the icy reading. The result is a rigorous scientific taxonomy — six-fold hexagonal symmetry, labeled axes, one specimen per cell — distinct from Bentley's white-on-white plates.