I know it's a slice of a lovely geode, but I can't for the life of me remember where or how I got it.
It's a purchased piece, not one found by the roadside, so I either bought it for myself or it was a gift. It's a slice about 1/3" thick, with the outside edge in its rough natural state, and its blue cross section has been polished smooth. The whole rock is about the size of a coaster.
Wherever it came from, I like it!
Camera: Canon 40D with 60mm macro lens and 430EX Speedlite, 1/30s, f/2.8 at ISO 800