Geodes: The History Within The Stone

AZ Nature

Geodes have been a phenomenon in the geological world for years. These rocks that are formed over millions of years look like every other rock on the outside, but on the inside lays a beautiful collection of crystals. Native to the Tucson area, you can visit a variety of places to see the beauty of these rocks and even have one of your own.

First things first, what is a geode and how are they created? A geode is a spherical rock that contains a hollow cavity in the middle that is lined with crystals. Other rocks, such as agates, that are completely filled with small compact crystals are called nodules. The primary difference between a geode and a nodule is that a geode has a hollow cavity and a nodule is one solid rock.

How geodes are made is what makes them so unique. Beginning as air bubbles in volcanic rock, animal burrows, tree roots or mud balls in sedimentary rock, the outer shell eventually hardens and forms the round shape of the rock. Once the outside is formed, mineral rich water forms on the inner walls of the hollow cavity within the geode. The water, containing silica precipitation, holds a variety of minerals, most commonly quartz, but amethyst and calcite are also found as well. Then over millions of years, layers of silica cool, thus forming the crystals inside the hollow cavity.

Each geode is unique in how it is created and it’s end composition, which can only be discovered by cracking the geode open. These unique geological wonders can be found all over the deserts of Arizona. While in the area, take a family trip to explore and discover these wonderful treasures. This can be a great way to do some family bonding and get some awesome souvenirs! But, if you’re pressed for time or not much of the adventurous type, there are a few places in the Tucson area where you can snag some geodes.

The first place to get your hands on some geodes is at the General Store in Trail Dust Town! This unique little town will take you back to the Wild West and is a great place to find small geodes and spend a day with the family. Another great place to get your hands on a variety of geodes and other awesome minerals is Tucson Mineral and Gem World. This place is loaded with all different types of rock so you are sure to find one that catches your eye.

Another perfect place to see and buy geodes and other beautiful stones is the Tucson Gem, Mineral and Fossil Showcase! It’s only offered two times a year so make sure to check it out while you can! This multi-location event gives you the chance to check out tons of fantastic gems. Most shows are free and open to the public so head on over!