| Term: | Grain |
| Definition: | (1) with respect to both shape and size of snow grains, the same as particle, i.e., the smallest characteristic subunit of snow microstructure recognizable with a hand lens (8-10x magnification). (2) One single crystal of ice making up the ice structure of snow. The crystal orientation is continuous across each individual grain. Several grains together form a polycrystal having grain boundaries where crystal orientation changes. |