Ice Horns

I don't know if these things have an official name, but they remind me of tiny horns. These tiny crystalline structures just look like soft fuzz or fine hairs until you see them though a macro lens. They are the horizontal fringe on the edges of medium-sized ice structures that I found hanging over some holes above riffles in a rocky brook. I imagine that water molecules in the moist air rising from the hidden brook crystallizes on objects when it hits the cold air.

Canon 5D2
Sigma 150 Macro
3.2 sec. @ f/16: ISO 100