This is a sea urchin skeleton from somewhere in the South Pacific. That's what the lady who sold it to me said, anyways, and I have no reason to doubt someone that sells things.
I lit it from above with a single off-camera flash with a softbox, and had a couple pieces of folded paper as reflectors to fill in light on the underside. In Lightroom, I painted out all the non-black stuff until I had a purely black background.
[last year] some of the coolest stuff I've ever seen...
From One/Day Project, Year 5