What Is a State Rock?

State Rocks: Geological Symbols of U.S. States

A state rock (or state mineral/gemstone) is an officially designated geological symbol representing a U.S. state. Selections reflect local geology, history, or economic importance.

Examples

• Arkansas: Novaculite (fine-grained quartz rock, used for whetstones).
• California: Serpentine (colorful metamorphic rock).
• Colorado: Aquamarine (blue-green beryl gemstone).
• Florida: Coquina (shell-based sedimentary rock).
• Georgia: Kyanite (blade-like blue aluminosilicate).
• Idaho: Star Garnet (pyrope garnet with asterism).
• Iowa: Geode (hollow rock lined with crystals).

Not all states have designated a state rock; some choose a state mineral or gemstone instead.