In honor of the winter and holiday season, I thought you might be interested in an article about the science of snowflakes.  Did you know that the shape snowflakes takes depends on the atmospheric conditions in which they form?  The most common snowflakes, which we make with paper and scissors in schoolrooms, are called dendrites, and form in a fairly narrow range of temperature and humidity conditions.  But there are many other shapes of snowflakes and ice crystals as well.  Here is an interesting article from the blog CompoundChem.com which describes the science behind the shapes (link).  Also check out these additional links:

CalTech’s snowflake primer

The physics of snowflakes

morphology of snowflakes