One day I noticed that the frozen slush next to the bike rack in front of the main entrance to the Geophysical Institute was quite interesting. I don't know if they've used ordinary salt to try to melt the snow and ice or if something else is added due to the low temperatures here. Whatever they put in it, the slush froze back up again, forming giant ice crystals during the freezing process. I regret not putting out a coin or something for comparison. The biggest ones were perhaps about the size of a quarter (a couple of centimeters), so 'giant' may not be the best word, but they were much bigger than anything you see in snow flakes. Click on thumbnails to view larger versions. The two last ones are full resolution (574 and 113KB respectively, the latter is a crop).
Side note: Once again I accidentally used ISO 800, but this time I believe it was my luck. It was late afternoon and the scene was not very well lit. With ISO 100 or 200 I feel pretty sure that the shutter speed would have been too low to get sharp pictures, considering the hands holding the camera were shaking because I was fooling around in the cold without a jacket. Now the camera chose exposure times around 1/200 sec. or less, yielding sharp photos in spite of shaky hands.