This is smallest ice crystals i've ever photographed. I think, bigger of them not large than 0,2 mm. Looks better in original resolution: 1024 x 768.
The story: in december 2012 in Moscow was a really cold week, without any snowflalls, clear skies day and night. While waiting for snow, i leave my glass surface outdoors, hoping to catch some flakes, if they fall at night. One morning i found it covered by ice dust, without any flakes visible by naked eye. As in this photo, i picked best looking crystals from whole frame and drag them in one compact group.
This is three in-camera jpeg's from this morning (please click on them to load full 12mp images):
Also i photographed transparent ruler (at same distance from the lens as snowflakes) and blended it to snowflake shot to see scale:
Next ice dust picture:
If you want to see more snowflakes, you can browse through all snowflake pictures.
Here you'll find snowflake photo wallpapers in numerous resolutions and screen proportions, up to Ultra HD 4K.
And here is article about snowflake macro photography.