Beauty on the Inside

My young niece, T, is a rock hound just like me.  I sent her several specimens for her birthday, including one of these geodes.  From the outside, these are not very impressive, but once cracked open, the crystal lining is quite breathtaking.  Her father sent me a short video of T breaking her geode open with a hammer.  Her audible gasp of delight mimicked mine.  Ahhhhh!