This is the image on the cover of the April 2008 issue of Geology:

Wow, eh? Here's what they have to say about it: "The image shows a perfectly preserved Devonian phacopid trilobite, which was collected at Hamar Laghdad in Morocco (cephalon is 10.2 mm diameter). The shell is silicified with a high iron content, while the lenses retained their original calcitic composition, hence the color difference. This can probably be explained by the different crystal size and the porosity of the shell. Photo by: Christian Klug and Hartmut Schulze."

Labels: art, fossils, minerals