Discover the Magic of Geodes: Nature’s Lucky Dip
What is a Geode?
A geode is a hollow rock lined with sparkling crystals that formed over millions of years. On the outside, it may look like an ordinary stone, but inside it holds a breathtaking surprise of glittering crystals.
At The Crystal Caves in Atherton, Queensland, you’ll find geodes in all shapes and sizes. From our giant AA-grade amethyst geode in the museum (one of the largest in the world!) to the smaller, spherical Mexican geodes that visitors can crack open themselves.
How Do Geodes Form?
Geodes begin as gas bubbles trapped inside cooling lava or as hollow pockets in sedimentary rock. Over millions of years, water rich in minerals like silica, iron, and calcium seeps into these empty spaces.
As the water evaporates, the minerals slowly crystallise, forming quartz, amethyst, calcite, agate and other crystal structures.
Where Do Geodes Come From?
Geodes are found all over the world, but we’ve been sourcing geodes from one of our longest-standing suppliers in Mexico for decades. They’re the best of the best: large, beautifully spherical, and filled with high-quality crystals.
Two varieties come from different mining areas in Chihuahua, Mexico:
- Trancas Geodes
- Generally smaller than Las Choyas.
- Most commonly contain quartz, calcite, and chalcedony (which can glow under black light).
- Favoured by collectors for their neat crystal structures and variety.
- Las Choyas Geodes
- Larger and more spherical, making them ideal for cracking.
- Often filled with clear quartz, smoky quartz, or amethyst.
- Sometimes contain calcite or other mineral inclusions for extra sparkle.
Crack Your Own Geode at The Crystal Caves
One of our most-loved experiences is the chance to crack open your very own geode.
It begins with choosing your geode. We have 3 sizes from the Tranca mine, and 3 sizes from the Choya mine for you to choose from, depending on preference and budget.
Then comes the excitement: placing it in our custom-built geode cracker, pulling down on the handle, and hearing that satisfying bang as it splits in half.
In that moment, you’ll be the very first person to see the crystals hidden inside for over 44 million years.
Our team will guide you through the formations inside, turning the discovery into a fun, hands-on geology lesson.
We offer a Sparkle Guarantee – so if your geode is solid or the crystals inside are a little dull, you’ll get another go!
Frequently Asked Questions About Geodes
Hidden FAQ
Are geodes the same as thunder eggs?
No. Thundereggs are found in Australia and are usually solid, without the hollow cavity of crystals. Geodes, by contrast, are hollow and lined with sparkling crystals.
Are geodes natural or man-made?
The geodes we crack at The Crystal Caves are 100% natural. No two are ever alike, making each one a one-of-a-kind discovery.
Do I need to be strong to crack a geode?
No. The collection displays crystals and fossils from all over the world. Just like visiting a zoo where some animals are only found in specific countries, so too is René’s collection of crystals and fossils from all over the world including several from Australia.
How do I choose a good geode?
We always recommend going for the lighter ones – they’re usually the most hollow and give the most sparkle inside. But if you get a dud, we let you crack again anyway.
Do I get to keep my geode after it’s cracked?
Absolutely! Every cracked geode is yours to take home as a souvenir. On rare occasions, if you open a truly exceptional geode, we might ask if you’d consider letting us buy it back from you to add it to René’s collection – but that’s completely up to you.