I shot this picture at Devils Marbles, an outcropping of rounded boulders formed by spheroidal weathering. That is, molten volcanic rock cooled very quickly, forming crystals as big as a living room. Overtime, the rock cracked across the crystal lines. From there, weather takes over, gradually eroding the corners and edges down until they're rounded.
But even that doesn't adequately describe the image. It's just plain cool.