Snow crystals are shaped by the conditions under which they form, particularly the air temperature in relation to humidity. "These factors not only affect how the crystals grow but the basic shape they take. The colder the temperature, the sharper the ice crystal tips. At warmer temperatures, the ice crystals grow more slowly and smoothly, resulting in less-intricate shapes, i.e., more needles and plates. Thus, dendrite crystals generally form in high clouds, needle or flat six-sided crystals often originate in middle height clouds, and a wide variety of shapes grow in low clouds."
--exceprt from Snowflakes by Keith C. Heidorn
These pictures show real
snow crystals that fell to earth; captured by Kenneth G. Libbrecht using a
specially designed snowflake photomicroscope.
To view more snow crystals, Libbrecht's technique, and to learn more about snow
crystals, visit SnowCrystals.com
http://www.its.caltech.edu/%7Eatomic/snowcrystals/photos/photos.htm
Cross-section of Cereus spp. Koch fractal, aka the "Koch snowflake" or the "Koch star"
J. D. Mauseth A.I.Studio