snow crystals

Ice crystals whose form depends on temperature and humidity; they fall separately or in agglomerations of flakes.

column

Short translucent ice crystal with flat extremities; it is prism-shaped and occasionally hollow.

plate crystal

Ice crystal in the form of a thin hexagonal plate that is occasionally hollow.

spatial dendrite

Ice crystal characterized by complex branches similar to those of a tree.

irregular crystal

Ice crystal with no defined shape resulting from the agglomeration of several crystals.

stellar crystal

Star-shaped crystal with six branches.

snow pellet

Opaque ice crystal less than 0.2 in in diameter that froze inside a cloud.

sleet

Ice crystal less than 0.2 in in diameter that results from rain drops or snow flakes freezing before they touch the ground.

hail

Hard, usually spherical ice crystal that varies between 0.2 and 2 in in diameter; it is formed of concentric layers of clear opaque ice.

capped column

Ice crystal that is identical to the column, except for the thin hexagon-shaped cap at each extremity.

needle

Translucent prism-shaped ice crystal; it is long and narrow and has pointed ends.