Snowflakes are collections of snow crystals that are loosely bound together. This linkage can express itself in plate-like forms like the light microscope view that is in the top middle row of the light microscope examples or middle -left in the scanning electron examples shown below. It is also possible to have column forms like the middle-left light microscope view or the bottom left SEM view.

The form that the crystal takes depends on the temperature and how supersaturated the water is at the point of growth. The hollow prisms and plates/dendrites that we are getting in the photos below are largely due to low temperatures coupled to varying degree of supersaturation.

A excellent source of further information on snow crystals and their growth can be found at this Caltech site.

The photographs on this page are what are termed acrylic replicas. Microscope slides and a can of clear acrylic spray are set out overnight. (This brings everything to snow-like temperatures so the snowflakes will not melt when they land on the slides.) The slide is lightly sprayed with acrylic spray and snowflakes are allowed to land. The spray will hold the snowflakes without dissolving them but still give an impression. When you have collected a number of flakes on the slide, allow the spray to dry before bringing it indoors. After the snowflake has melted you are left with a "fossil" or impression which you can look at under the microscope.

The composite photograph shown below is the same dendritic snowflake under reflected light and then under transmitted light. The slide is "Sputter-coated" with gold and examined under the Scanning Electron Microscope (SEM).

Composite View