* Geodes are formed through a process called secondary mineralization**. This means they form within pre-existing rocks, often within cavities or voids. The minerals that make up the geode crystallize from solutions that seep into these cavities.

* Metamorphic rocks are formed when existing rocks (igneous, sedimentary, or even other metamorphic rocks) are subjected to intense heat and pressure, causing changes in their mineral composition and texture.

Here's a simple breakdown:

* Geode: A rock with a hollow interior lined with crystals, formed through secondary mineralization.

* Metamorphic Rock: A rock that has undergone transformation due to heat and pressure, changing its mineral composition and texture.

While a geode might be found within a metamorphic rock, the geode itself is not formed by the metamorphic process.