Here's why:

* Formation: Geodes form when gas bubbles or cavities within volcanic rock become filled with mineral-rich water. Over time, the water evaporates, leaving behind the crystals that form the geode's interior.

* Crystals: The crystals inside geodes are formed through a process called crystallization, where minerals dissolved in the water precipitate out and solidify. This process doesn't involve trapping water within the geode.

* Dryness: The interior of a geode is typically dry and can even be quite dusty.

However, there are a few points to consider:

* Tiny amounts of moisture: There might be trace amounts of moisture trapped within the crystal structure of the geode. This is extremely small and won't be visible to the naked eye.

* Geodes found in water: Some geodes might be found in areas where they are exposed to water, like near rivers or lakes. However, this doesn't mean the geode itself contains water.

Overall, while geodes are formed from water, they don't contain any significant amount of water once the crystallization process is complete.