J.M.W. Turner – Death on a Pale Horse
Yang Yongliang – Moonlight; the landscape without light (large version here)
Sebastian Evans – The Ancients of the World (c.1870)
Mind-bending Sierpinski-related fractal visualizations (56k warning)
A chiton’s teeth– made of the hardest material produced by any living organism, magnetite.
Odilon Redon – Cyclops (1914)