Iowa does not have an official state gemstone. Instead, the state of Iowa has designated the geode as its official state rock.
Iowa's State Designations
While many U.S. states have official gemstones, Iowa has chosen to highlight a different geological formation unique to its region. According to official designations, Iowa has a state rock but no specific state gemstone or mineral.
The official records indicate the following for Iowa:
| State | Mineral | Rock or Stone |
|---|---|---|
| Iowa | Geode (1967) |
As documented, the geode was officially recognized as Iowa's state rock in 1967. The designation table specifies "Rock or Stone" for the geode, and the "Mineral" column (where gemstones would typically be listed) remains blank for Iowa.
What is a Geode?
A geode is a remarkable geological rock formation characterized by a hollow cavity lined with crystals. These unique natural wonders are particularly abundant in southeastern Iowa, making the state a prime location for geode enthusiasts and collectors. The outer shell of a geode is typically composed of limestone or a similar rock, while the internal cavity can contain various crystal formations. Commonly found crystals within geodes include quartz (which encompasses varieties like amethyst and citrine), calcite, or dolomite. Despite containing valuable crystals, the geode itself is classified as a rock formation rather than a single gemstone.
