When our snow melted slightly in the sunlight, then refroze overnight, it made beautiful ice feathers. Apparently these hoarfrost* ice crystals are made from single tiny columns of ice, but since some of them grow at angles to the others, they create a feathered shape.
Here’s a way to make candy "frost" crystals in your kitchen from CANDY EXPERIMENTS BOOK 2:
Mix 1 tbps water with 3 tbsp xylitol, heating and stirring until the xylitol dissolves completely. Pour half the solution into a second bowl and put both bowls aside for several hours. The thin film of xylitol should crystallize into feathery patterns.
I also found a fun experiment for growing your own hoarfrost crystals at Snowcrystals.com
*Hoarfrost (a new vocab word for me!): A deposit of interlocking ice crystals (hoar crystals) formed by direct deposition on objects