Loot geodes adds tiny geodes that generate underground similarly to ores. They function similarly to breakable pots found in many other mods, with one important change. Rather than dropping all of their loot when mined, they instead drop chunks. These can be thrown as a projectile, and will burst into loot when hitting a block. This way, your inventory won't be completely filled during cave explorations.
By default, geodes contain ores and rarely enchanted books, golden apples and their respective shards. Nether geodes also contain materials such as blaze powder and obsidian.