
Awesome snowflake photography here.
This site has twelve-sided flakes, triangular flakes, bullet shaped, arrow-heads, and a weird twin-prism:

Johannes Keppler first published “On the Six-Cornered snowflake” in 1611. Descartes followed in 1635 with an accurate description of the morphology of the snow crystal. Robert Hooke in 1665 published a series of drawings he’d made of snowflakes after viewing a number of examples with the new-fangled microscope.
