Agate is a rock consisting primarily of cryptocrystalline silica. Agate is characterized by its fineness of grain and variety of color. Agates are classically associated with volcanic rocks and can be common in certain metamorphic rocks. Agate is thought to increase inner stability, composure, maturity, and help with protection.
A geode is a round rock which contains a hollow cavity lined with crystals. They can have many different crystals on the inside, but the most common one is quartz. Geodes are thought to improve intellectual insight, awareness, and community spirit.