Cracking a Geode is comprised of three popular methods:
Cracking Geodes with a cold chisel and sledge hammer. This method involves hitting your Geode squarely with a sharp chisel and crack hammer. It is very important to wear safety goggles. This method often creates fragments of rock and can be quite messy.
A large 14-16" circular rock saw often found at lapidary shops or wet saw can be used to cut your Geode. This will result in a smooth edge cut often desirable amongst retail collectors. In addtion, slices of Geodes can be made relatively easily and are often great display pieces.
Cracking a Geode with a large commercial soil Pipe Cutter. This is our favorite way to crack large Geodes and works rather well. The crack is rustic and often follows the natural Geode lines so that little damage is done during the Geode cracking process. Below is a video of an actual Geode cracking.
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The above video shows how to crack a Geode with a 36" chain commercial soil Pipe Cutter. The Geode is approximately 8 inches in diameter. The chain is wrapped around the circumference of the Geode and tightens gradually until the shear forces breaks the Geode in half. This particular Geode was found in Indiana and was not a "rattler".
The Pipe Cutter works by creating a circle of pressure points around the circumference of the Geode. As the levers are compressed the chain tightens and the points etch the Geode with tremendous pressure. Repetition of compression and tightening of the soil Pipe Cutter chain results in distributed pressure around the exterior of the Geode. Ultimately, the Geode breaks along the pressure point line and creates a piezoelectric spark which can be clearly seen in the video.
Before Cracking Geodes, you gotta Clean your Geodes!
Cracking Geodes is hard work but lots of fun! Learning the best way to crack a Geode takes practice. Whether you try your hand at using a custom Geode cutter, wet saw, or a simple chisel always wear eye protection and be careful. Discover the rewards of Geode hunting outdoors.
Get out and rockhound!
Did you know? Geodes
Latin and Greek derivation meaning precious stone and earthlike.