Cracking 10 geodes open to see what lives inside! While we wait for the rocks to finish tumbling, I got some geodes! Geodes are hollow rocks where beautiful crystals form. In order for a geode to form, rocks have tiny holes that groundwater carrying minerals seeps into and once layers build up inside the rock, crystals form! They’re also found in volcanoes when gas from lava gets trapped in the holes of the rocks and crystals appear. These processes take millions of years! I’m going to get a ham