Looks like the inside of a geode. They are very different from each other. What does the other side look like?
All geodes have thin outer shells.Hmm...a geode with a thin outer shell. Interesting!!
Ok, let me re-phrase that - I've seen lots of geodes that have the thin shell, but also have some solid rock with the geode center. With this one, it seems there's a thin shell and the crystals.All geodes have thin outer shells.