Interesting shot, is this a round or flat marble? Considering the closeness and flatness I would've went for a less identifiable reference or caption.
Brian, when I first saw the image, I thought it might be a photo taken from a spacecraft (despite the title!).
I know nothing about microscopy. If you'd used a smaller aperture would that have increased the depth of field? I like the way that the swirls tend to circle around a centre point.
When I can afford a spaceship i promise you will get real shots from space.
I am sure it would have. My limiting factor is that the Celestron InfiniView Digital Microscope has no way (at least that I have found) to adjust aperture. I can increase and decrease light and that will effect the ISO but that seems to be the only madjustment I can make with their setup which is locked onto AE.