The Origin of Geodes - How Geodes are Formed

The Origin of Geodes - How Geodes are Formed

Geodes are a fascinating geological phenomenon. They're essentially encapsulated bubbles with crystals inside! Geologists have been trying to figure out the origin of geodes for centuries, and there are many theories about how they form. In this blog post we will explore some of these theories, as well as more information about what exactly geodes are.


Geodes were created by water depositing crystals or amethyst in a cavity. Geodes form in cavities, such as caves and rocks that are already hollowed out by water or wind erosion with pore spaces big enough for crystals to grow into it. As crystals grew inside the geode's cavity they continued to accumulate until they were too heavy to stay put and the crystals would be deposited on the floor of the cavity.

- Geodes can also form as a result of volcanic rock that contains isolated pockets with crystals growing from wall to wall, or even an entire underground geode which is formed by super heated gas and steam turning into lava under water and then cooling down quickly enough for crystals to grow inside it.

- Geodes are also created by chemical deposition. As crystals grow, other minerals will stick to the crystals and form a lining in the geode's pocket. Sometimes this process can be witnessed through bacterial growth that creates small crystals on the outside of an amethyst geode!

What is a Geode? A geode is essentially a hollowed out rock that contains crystals.

- Geodes can range in size and shape, but the most common geode is spherical with crystals lining its inner cavity.

Geodes are found all around the world and at Crystal Joys we source them and sell them both online and in our stores. 

- In North America they're mostly seen near Mexico City where there's a large amount of volcanic activity nearby.

- In Asia, geodes are found all around Myanmar and the Himalayan mountains.

- Geodes can be seen in most countries of Europe, Africa, South America and Australia!

Why Do crystals grow inside a geode? Crystals will grow into any kind of pore space that's big enough for it to form. The crystals inside the geode will continue to grow and accumulate until they are too heavy for the cavity.

What is an Amethyst Geode? An amethyst geode is a hollowed out rock that contains crystals, specifically crystals of purple amethyst!

- The crystals on these rocks don't just come from one type of mineral; they come from many crystals that have grown together to form an amalgam.

- Amethyst geodes often contain other crystals, as well as small pieces of quartz and also the mineral dolomite or calcite which is white in color!