Triangular Snow Crystal
December 25, 2013
Provided By: The Schwerdtfeger Library
Summary Author: Jim Foster
Not all snow crystals look like the ones on store-front windows. The odd, triangular crystal featured above has arms that are obviously unequal in length, but it still has a hexagonal shape. So even thought the sides are dissimilar, the angles are nonetheless all the same (60 degrees). Note that the innermost hexagonal shape is very close to being symmetrical.
It’s been observed that plate-type crystals may on rare occasions assume triangular shapes when the air temperature is a little below freezing (27 F or -3 C) –- the reason for this isn’t clear. The corners of this particular crystal sprouted the miniature plates as it neared the surface.
Merry Christmas and Happy Holidays from the staff of the Earth Science Picture of the Day
Erin Carver, Stu Witmer, Jim Foster