Geode Jewelry

To give geodes some additional usage, you should be able to craft jewelry and amulets out of them. this could help flesh out the magical/fantasy side of Minecraft, and give players more items to explore and grind for. 

Amulets and jewelry should give you some small benefit, like a heart of absorption, a little bit of extra saturation, or some resitance. these should only be effective when worn in a special offhand, to balance this mechanic.