Snow Crystal

snow crystal

[′snō ‚krist·əl]
(meteorology)
Any of several types of ice crystal found in snow; a snow crystal is a single crystal, in contrast to a snowflake which is usually an aggregate of many single snow crystals.

Snow Crystal

 

a crystal of ice that falls from the clouds and mists in which it formed. Snow crystals occur in two basic forms: tabular and prismatic. Tabular crystals include hexagonal plates and stellar crystals with three, six, or 12 rays. Prismatic crystals include hexahedral columns and needles, as well as clusters of columns called spatial dendrites. Snow crystals often have irregular shapes. The dimensions and shapes of snow crystals vary greatly, depending on the physical conditions of formation and growth (most importantly, the air temperature and humidity). At higher temperatures, the dimensions of the crystals and the proportion of tabular shapes increase. Snow crystals most often have the form of stars and spatial dendrites. Stars with acicular rays reach 6-8 mm across; those with tabular rays are 4–5 mm across. Spatial dendrites are 2-3 mm across; plates, 1–2 mm across; columns, 1–2 mm long; and needles, 3-5 mm long. Large snow crystals falling from clouds are called snowflakes; they most commonly take the shape of stars.

Snow crystals result from the sublimation of water vapor on frozen drops of clouds and mists or on crystalline dust particles. Small cloud crystals have the simple shapes of plates or columns. Shapes usually become more complex when the crystals reach dimensions of 0.1–0.2 mm. Strong winds break snow crystals down to dimensions of 0.1 mm or less. Graupel forms when snow crystals fall through a cloud containing supercooled drops of water. [23–1885–]

References in periodicals archive ?
It is conceivable, that rolled up particles also contain fragments of a dendrite, a needle or any other snow crystal.
Bentley made the first microphotograph of a snow crystal in 1885.
Make a full-size motif of the Snow Crystal Quilting and mark it in the blocks and patches as shown.
Tenders are invited for Provision and display of 3D view design & SS buffed stands with 3D snow crystal.
He noticed that, as a snow crystal develops at -15[degrees], the top edge starts to grow a little bump of a ledge, which gets sharp at the tip.
Snowflakes are a general term for snow crystals and can mean the single snow crystal or two or more crystals stuck together floating from the sky.
That is because certain weather conditions, together with the path the snowflake takes from sky to ground, dictate the shape of the snow crystal.
By adding or subtracting heat, for instance - just like in the kitchen - you can make different snow crystal shapes.
What kept coming up revolved not around skiing or how many sides a snow crystal has, but rather how snow is slippery, how it turns to ice, why school is closed on snow days, why cars get stuck in the snow, why we shovel snow, how we get around when it snows, and why the snow turns so brown and gets so dirty.
A snow crystal is born when a water droplet condenses and freezes around a bit of dust or ice inside a cold cloud.
By the age of 19, he had taken the very first photo-micrograph of a snow crystal.
River Lena has run two solid races in defeat and was unlucky to come up against a potentially useful type in Snow Crystal at Yarmouth.