Under some atmospheric conditions, forming and descending snow crystals may encounter and pass through atmospheric supercooled cloud droplets. Contact between the snow crystal and the supercooled droplets results in freezing of the liquid droplets onto the surface of the crystals. This process of crystal growth is know as accretion. Crystals that exhibit frozen droplets on their surfaces are referred to as rimed. When this process continues so that the shape of the original snow crystal is no longer identifiable, the resulting crystal is referred to as graupel.

A striking high detail image of rime (frost) on both ends of a column-shaped snow crystal. Again, the 24 MB source file is linked on the image description page, if anyone wants to improve the sharpness/lighting/contrast.

Promoted Image:Snowflake 300um LTSEM, 13368.jpg Raven4x4x 09:48, 1 August 2006 (UTC)[reply]